X9.3 Flare blasts off the Sun. Image credit: NASA/GSFC/SDO
An X9.3 class solar flare flashes in the middle of the Sun on Sept. 6, 2017. Credit:NASA/GSFC/SDO
If you’re still riding that high from seeing the recent total solar eclipse and you want to keep the party going, now’s your chance to see another of the night sky’s wonders: an aurora. That said, a totally full Moon is going to try and wreck the party.
NASA announced that two powerful flares were just emitted on the surface of the Sun, casting coronal mass ejections in our direction. Over the course of the next couple of days, this should generate aurora activity in the sky outside the regular viewing areas. In other words, if you normally don’t see the Northern Lights where you live, you might want to spend a few hours outside tonight and tomorrow. Look up, you might see something.
The first flare, an X2.2 event, peaked on September 6 at 5:10 am EDT and the second X9.3 flare went off at 8:02 am. Both of which came from the sunspot group AR 2673. If you’ve still got those eclipse glasses, take a look at the Sun, and you should be able to see the sunspot group right now. There are two groups of sunspots close to one another, AR 2673 and AR 2674. This follows up the X4 flare emitted on September 4th.
Solar astronomers measure flares using a similar scale to other natural events, with a series of designations. The smallest are A-class, then B, C, M and finally X. Each level within the rating accounts for double the strength; it’s exponential. So, and X2 is twice as powerful as an X1, etc. The most powerful flare ever recorded was an X28 in 2003, so today’s flare is still comparatively weak to that monster. Here’s the flare in visible and ultraviolet. Credit: NASA/GSFC/SDO
But, measuring in at X9.3, today’s flare is the strongest in almost a decade. The last one this strong was back in 2008. And NOAA is predicting that this flare could cause radio blackouts across the sun-facing side of the Earth. If you’re out at sea and depending on your radio transmissions, don’t be surprised if you’re getting a lot of static today.
How do you stand the best chance of seeing auroras? My favorite tool comes from NOAA’s 3-day aurora forecast. It shows you a 3-day predictive simulation for what the solar storm should do as it buffets the Earth’s magnetosphere. You can run the simulation backwards and forwards, and you’re looking glowing green areas to come across your part of the world.
But even if it doesn’t look like you’re going to see the auroras, I still think it’s worth trying. Even if you don’t get an aurora directly overhead, you can sometimes see it on the horizon, and it can be surprisingly beautiful.
Here’s my timelapse video of auroras on the horizon.
The big problem, of course, is the Moon. Tonight is also a full Moon, which means that awful glowing ball is going to rise just after sunset and blaze across the sky all night. You’re going to have a rough time seeing all but the brightest auroras. But I still think it’s worth trying.
If you want to maximize your chances of seeing an aurora, check out the Space Weather site on a regular basis. There are also services that’ll send you a text message when there’s a powerful aurora going on in your area (just Google “aurora alert text messages”. And of course, there are handy apps that’ll make your phone beep boop when there are auroras overhead. I use an app called Aurora Alert.
We’ve had three powerful flares in the last couple of days, which means that the Sun is feeling a little frisky. There could be more, and they could happen after the full Moon is over, and we’ve got some alone time with the dark sky. So stay on top of the current space weather, spend time outside, and keep your eyes on the sky. You might get a shot at seeing an aurora.
The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime view of the Category 5 Hurricane Irma in the early hours of September 5, 2017. When the image was acquired, the storm’s center was moving due west. A National Hurricane Center forecast called for the hurricane to turn west-northwest toward the northern Leeward Islands. Credit: NASA, NOAA, Suomi NPP - VIIRS.
Record-setting Hurricane Irma barreled over the Caribbean islands of St. Martin, St. Barthelemy and Anguilla early Wednesday, destroying buildings with its sustained winds of 185 mph (297 kph), with rains and storm surges causing major flooding. The US National Hurricane Center listed the Category 5 Irma as the strongest Atlantic hurricane ever recorded north of the Caribbean and east of the Gulf of Mexico. The storm continues to roar on a path toward the U.S. and British Virgin Islands, Puerto Rico and possibly Florida, or along the southeast coast of the US.
This animation of NOAA’s GOES East satellite imagery from Sept. 3 at 8:15 a.m. EDT (1215 UTC) to Sept. 6 ending at 8:15 a.m. EDT (1215 UTC) shows Category 5 Hurricane Irma as it moved west and track over St. Martin by 8 a.m. EDT on Sept. 6:
Different models have Irma traveling on slightly different paths and officials from all the areas that might possibly be hit are telling people to prepare and follow evacuation orders. National Hurricane Center scientist Eric Blake said via twitter that some models had the storm going one way, and some another. But he cautioned everyone in a potential path should take precautions. “Model trends can be quite misleading- could just change right back. It is all probabilistic at this point. It could still miss [one particular area]. But chances of an extreme event is rising.”
The fleet of Earth-observing satellites are providing incredible views of this monster storm, and even astronauts on board the International Space Station are capturing views:
The International Space Station’s external cameras captured a dramatic view of Hurricane Irma as it moved across the Atlantic Ocean Sept. 5. pic.twitter.com/mc61pt2G8O
GOES-16 view of #HurricaneIrma at 30-second intervals covering 5-hour period ending at 352 AM CDT (9/6), including its passage over Barbuda. pic.twitter.com/WL6l6klPKw
While satellite views provide the most comprehensive view of Irma’s potential track, there’s also a more ‘hands-on’ approach to getting data on hurricanes. NOAA hurricane hunter Nick Underwood posted this video while his plane flew into Hurricane Irma yesterday. The plane’s specialized instruments can take readings on the storm that forecasters can’t get anywhere else:
In the meantime, a launch is scheduled from Cape Canaveral on Thursday, September 7. SpaceX is hoping to launch the US Air Force’s X-37B reusable spaceplane, but current forecasts put only a 50% chance of weather suitable enough on Thursday, and only 40% on Friday. We’ll keep you posted.
For the latest satellite views, the Twitter accounts above are posting regular updates.
On Sept. 4 at 17:24 UTC, NASA-NOAA’s Suomi NPP satellite captured this view of Hurricane Irma as a Category 4 hurricane approaching the Leeward Islands. Credits: NOAA/NASA Goddard MODIS Rapid Response Team.
Molecular clouds scattered by an intermediate black hole show very wide velocity dispersion in this artist’s impression. This scenario well explains the observational features of a peculiar molecular cloud CO-0.40-0.22. Credit: Keio University
At the center of the Milky Way Galaxy resides the Supermassive Black Hole (SMBH) known as Sagittarius A*. This tremendous black hole measures an estimated 44 million km in diameter, and has the mass of over 4 million Suns. For decades, astronomers have understood that most larger galaxies have an SMBH at their core, and that these range from hundreds of thousands to billions of Solar Masses.
However, new research performed by a team of researchers from Keio University, Japan, has made a startling find. According to their study, the team found evidence of a mid-sized black hole in a gas cluster near the center of the Milky Way Galaxy. This unexpected find could offer clues as to how SMBHs form, which is something that astronomers have been puzzling over for some time.
This artist’s concept shows a galaxy with a supermassive black hole at its core. The black hole is shooting out jets of radio waves.Image credit: NASA/JPL-Caltech
This compact dust cloud, which has been a source of fascination to astronomers for years, measures over 1000 AU in diameter and is located about 200 light-years from the center of our galaxy. The reason for this interest has to do with the fact that gases in this cloud – which include hydrogen cyanide and carbon monoxide – move at vastly different speeds, which is something unusual for a cloud of interstellar gases.
In the hopes of better understanding this strange behavior, the team originally observed CO–0.40–0.22 using the 45-meter radio telescope at the Nobeyama Radio Observatory in Japan. This began in January of 2016, when the team noticed that the cloud had an elliptical shape that consisted of two components. These included a compact but low density component with varying velocities, and a dense component (10 light years long) with little variation.
After conducting their initial observations, the team then followed up with observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. These confirmed the structure of the cloud and the variations in speed that seemed to accord with density. In addition, they observed the presence of radio waves (similar to those generated by Sagittarius A*) next to the dense region. As they state in their study:
“Recently, we discovered a peculiar molecular cloud, CO–0.40–0.22, with an extremely broad velocity width, near the center of our Milky Way galaxy. Based on the careful analysis of gas kinematics, we concluded that a compact object with a mass of about 105 [Solar Masses] is lurking in this cloud.”
Change image showing the area around Sgr A*, where low, medium, and high-energy X-rays are red, green, and blue, respectively. The inset box shows X-ray flares from the region close to Sgr A*. NASA: NASA/SAO/CXC
The team also ran a series of computer models to account for these strange behaviors, which indicated that the most likely cause was a black hole. Given its mass – 100,000 Solar Masses, or roughly 500 times smaller than that of Sagittarius A* – this meant that the black hole was intermediate in size. If confirmed, this discovery will constitute the second-largest black hole to be discovered within the Milky Way.
This represents something of a first for astronomers, since the vast majority of black holes discovered to date have been either small or massive. Studies that have sought to locate Intermediate Black Holes (IMBHs), on the other hand, have found very little evidence of them. Moreover, these findings could account for how SMBHs form at the center of larger galaxies.
In the past, astronomers have conjectured that SMBHs are formed by the merger of smaller black holes, which implied the existence of intermediate ones. As such, the discovery of an IMBH would constitute the first piece of evidence for this hypothesis. As Brooke Simmons, a professor at the University of California in San Diego, explained in an interview with The Guardian:
“We know that smaller black holes form when some stars die, which makes them fairly common. We think some of those black holes are the seeds from which the much larger supermassive black holes grow to at least a million times more massive. That growth should happen in part by mergers with other black holes and in part by accretion of material from the part of the galaxy that surrounds the black hole.
“Astrophysicists have been collecting observational evidence for both stellar mass black holes and supermassive black holes for decades, but even though we think the largest ones grow from the smallest ones, we’ve never really had clear evidence for a black hole with a mass in between those extremes.”
Artist’s impression of two merging black holes, which has been theorized to be a source of gravitational waves. Credit: Bohn, Throwe, Hébert, Henriksson, Bunandar, Taylor, Scheel/SXS
Further studies will be needed to confirm the presence of an IMBH at the center of CO–0.40–0.22. Assuming they succeed, we can expect that astrophyiscists will be monitoring it for some time to determine how it formed, and what it’s ultimate fate will be. For instance, it is possible that it is slowly drifting towards Sagittarius A* and will eventually merge with it, thus creating an even more massive SMBH at the center of our galaxy!
Assuming human beings are around to detect that merger, its fair to say that it won’t go unnoticed. The gravitational waves alone are sure to be impressive!
The Soyuz MS-04 vehicle is pictured the moment it touches down with the Expedition 52 crew inside comprising NASA astronauts Peggy Whitson and Jack Fisher and Commander Fyodor Yurchikhin of Roscosmos on Sept. 3, 2017, Kazakhstan time. Credit: NASA/Bill Ingalls
The Soyuz MS-04 vehicle is pictured the moment it touches down with the Expedition 52 crew inside comprising NASA astronauts Peggy Whitson and Jack Fisher and Commander Fyodor Yurchikhin of Roscosmos on Sept. 3, 2017, Kazakhstan time. Credit: NASA/Bill Ingalls
NASA’s Peggy Whitson, America’s most experienced astronaut, returned to Earth safely and smiling Sunday morning on the steppes of Kazakhstan, concluding her record-breaking stay in space aboard the International Space Station (ISS) along with Soyuz crewmates Jack Fischer of NASA and Commander Fyodor Yurchikhin of Roscosmos.
The multinational trio touched down softly on Earth inside their Soyuz MS-04 descent capsule on Saturday evening, Sept. 2 at 9:21 p.m. EDT (shortly after sunrise 7:21 a.m. Kazakhstan time, Sept. 3), some 90 miles southeast of the remote town of Dzhezkazgan in Kazakhstan.
Whitson wrapped up a 288-day extended mission in obviously good health that began in November 2016, spanning 122.2 million miles and 4,623 orbits of Earth – completing her third long-duration stay on the orbiting science outpost spanning Expeditions 50, 51 and 52.
“A flawless descent and landing,” said NASA commentator Rob Navias during the live NASA TV coverage of the return of the ISS Expedition 52 crew Saturday afternoon and evening US time.
“The crew is back on Earth safe and sound.”
NASA astronaut Peggy Whitson, Russian cosmonaut Fyodor Yurchikhin of Roscosmos, and NASA astronaut Jack Fischer undergo routine initial medical checks after returning from their mission aboard the International Space Station at 9:21 p.m. EDT Saturday, Sept. 2, 2017 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), landing southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV
She has now accrued a total of 665 days in space – more than any American astronaut – over the course of her illustrious career during which she set multiple U.S. space records spanning a total of three spaceflights.
Whitson’s 665 total accumulated days in space places her eighth on the all-time space endurance list – just 8 days behind her Russian crewmate and Soyuz Commander Fyodor Yurchikhin who now ranks 7th on the all-time list with 673 days in space on his five flights. She has exceeded the endurance record of her next closest NASA competitor by 131 days – namely NASA astronaut Jeff Williams.
The remarkable 57-year-old Ph.D biochemist by training has spent nearly 2 years of her entire life in space and she holds several other prestigious records as well – including more accumulated time in space than any other woman and the longest single spaceflight by a women – 288 days!
During this mission Whitson became the first woman to serve twice as space station commander. Indeed in 2008 Whitson became the first woman ever to command the space station during her prior stay on Expedition 16 a decade ago. Her second stint as station commander this mission began earlier this year on April 9.
Whitson also holds the record for the most spacewalks and the most time spent spacewalking by a female astronaut. Altogether she has accumulated 60 hours and 21 minutes of EVA time over ten spacewalks -ranking her third most experienced in the world.
Notably Soyuz Commander Yurchikhin ranks fourth in spacewalking experience. Only Russia’s Anatoly Solovyev and NASA’s Michael Lopez-Alegria have more spacewalking time to their credit.
NASA’s Jack Fischer completed his rookie spaceflight accumulating 136 days in space aboard the ISS.
Astronaut Peggy Whitson is pictured May 12, 2017, during the 200th spacewalk at the International Space Station. Credit: NASA
Whitson originally launched to the ISS on Nov 17, 2016 aboard the Russian Soyuz MS-03 spacecraft from the Baikonur Cosmodrome in Kazakhstan, as part of the three person Expedition 50 crew including flight engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency).
Her flight was unexpectedly extended in flight after the Russian government decided to cut back on the number of space station crew cosmonauts this year from three to two to save money. Thus a return seat became available on this Soyuz MS-04 return flight after NASA negotiated an extension with Rosmoscos in April enabling Whitson to remain on board the orbiting outpost an additional three months beyond her than planned June return home.
Whitson’s mission extension proved to be a boon for NASA and science research enabling the US/partner USOS crew complement to be enlarged from three to four full time astronauts much earlier than expected. This allowed NASA to about double the weekly time devoted to research aboard station – a feat not expected to happen until America’s commercial crew vehicles, namely Boeing Starliner and SpaceX Crew Dragon – finally begin inaugural launches next year from the Kennedy Space Center in mid-2018.
NASA Astronaut Peggy Whitson after safe return to Earth on Sept. 2, 2017 ET. Credit: NASA
Descending dramatically while hanging below a single gigantic orange-and-white parachute the scorched Russian Soyuz vehicle fired its braking rockets just moments before touchdown in Kazakhstan to cushion the crew for a gentle landing under beautifully sunny skies.
A live NASA TV video feed captured the thrilling descent for over 14 minutes after the main parachute deployed all the way to the ground under clear blue sunny Sunday morning weather conditions and comfortably local Kazakh temperatures of 77 degrees F.
“Everything today went in perfect fashion from the undocking, to the deorbit burn to landing,” said Navias. “It went by the book with no issues.”
“We saw a spectacular 14 minute long live video of the Soyuz descent and landing.”
The Soyuz MS-04 carrying NASA astronauts Peggy Whitson and Jack Fischer and Fyodor Yurchikin of Roscosmos back to Earth from the International Space Station touched down at at 9:21 p.m. EDT Saturday, Sept. 2 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV
Russian search and recovery forces quickly arrived via a cluster of MI-8 helicopters after the soft landing to begin their normal procedures to extract the three Expedition 52 crew members from their cramped Soyuz descent module.
Soyuz Commander Yurchikhin in the center seat was hauled out first, followed by Fischer in the left side seat and lastly Whitson in the right seat. All 3 were placed on reclining seats sitting side by side and appeared quite well, conversing and speaking via satellite phones.
A group of Russian and US medical teams were on hand to check the astronauts and cosmonauts health and help the crewmates begin readapting to the tug of Earth’s gravity they have not experienced after many months of weightlessness in space.
Whitson’s final planned news conference from space with the media to sum up her experiences this past Wednesday had to be cancelled due to the catastrophic flooding events from Hurricane Harvey impacting Houston and elsewhere in Texas – including Mission Control which was forced to close multiple days.
The crews had bid their final farewells earlier and closed the hatches between the Soyuz and station at 2:40 p.m. EDT Saturday.
After conducting final spacecraft systems checks the trio unhooked the latches and undocked from the International Space Station at 5:58 p.m. EDT to begin their voyage home through the scorching heats of reentry in the Earth’s atmosphere that reached over 2500 degrees F (1400 degrees C) on the outside.
“While living and working aboard the world’s only orbiting laboratory, Whitson and Fischer contributed to hundreds of experiments in biology, biotechnology, physical science and Earth science, welcomed several cargo spacecraft delivering tons of supplies and research experiments, and conducted a combined six spacewalks to perform maintenance and upgrades to the station,” said NASA.
“Among their scientific exploits, Whitson and Fischer supported research into the physical changes to astronaut’s eyes caused by prolonged exposure to a microgravity environment. They also conducted a new lung tissue study that explored how stem cells work in the unique microgravity environment of the space station, which may pave the way for future stem cell research in space.”
“Additional research included an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment, and the study of plant physiology and growth in space using an advanced plant habitat. NASA also attached the Cosmic Ray Energetics and Mass Investigation (ISS CREAM) on the outside of the space station in August, which is now observing cosmic rays coming from across the galaxy.”
Astronaut Peggy Whitson signs her autograph near an Expedition 50 mission patch attached to the inside the International Space Station. Credit: NASA
ISS Expedition 53 began at the moment of undocking from the space station, now under the command of veteran NASA astronaut Randy Bresnik since the official change of command ceremony on Friday.
Along with his crewmates Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency), the three-person crew will operate the station for the next 10 days until the imminent arrival of three new crew members.
The station will get back to a full complement of six crewmembers after the upcoming Sept. 12 launch and fast track 4 orbit 6 hour docking of NASA astronauts Mark Vande Hei and Joe Acaba of NASA and Alexander Misurkin of Roscosmos aboard the next Soyuz MS-06 spacecraft departing from the Baikonur Cosmodrome, Kazakhstan.
Peggy Whitson set the record on Sept. 2, 2017, for most cumulative days living and working in space by a NASA astronaut at 665 days. Credit: NASAExpedition 52 Flight Engineer Peggy Whitson of NASA, Commander Fyodor Yurchikhin of the Russian space agency Roscosmos and Flight Engineer Jack Fischer of NASA float through the Harmony module of the International Space Station. Credits: NASA
Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news. Ken Kremer
Soyuz has split into 3 modules 139.8 km above Earth. Crew parachutes to landing inside Descent Module at 9:22 pm ET Sept. 2, 2017. Credit: NASAExpedition 52 crew returns to Earth Sept. 2, 2017. Credit: NASAPeggy Whitson @AstroPeggy is 3rd place all-time for cumulative spacewalk time with 10 spacewalks totaling 60 hours, 21 minutes. Credit: NASA
A billion years after the big bang, hydrogen atoms were mysteriously torn apart into a soup of ions. Credit: NASA/ESA/A. Felid (STScI)).
In accordance with the Big Bang model of cosmology, shortly after the Universe came into being there was a period known as the “Dark Ages”. This occurred between 380,000 and 150 million years after the Big Bang, where most of the photons in the Universe were interacting with electrons and protons. As a result, the radiation of this period is undetectable by our current instruments – hence the name.
Astrophysicists and cosmologists have therefore been pondering how the Universe could go from being in this dark, cloudy state to one where it was filled with light. According to a new study by a team of researchers from the University of Iowa and the Harvard-Smithsonian Center for Astrophysics, it may be that black holes violently ejected matter from the early Universe, thus allowing light to escape.
Their study, titled “Resolving the X-ray emission from the Lyman continuum emitting galaxy Tol 1247-232“, recently appeared in the Monthly Notices of the Royal Astronomical Society. Led by Phillip Kaaret, a professor of Physics and Astronomy at the University of Iowa – and supported by an award from the Chandra X-ray Observatory – the research team arrived at this conclusion by observing a nearby galaxy from which ultraviolet light is escaping.
Milestones in the history of the Universe, from the Big Bang to the present day. Credit: NAOJ/NOAO
This galaxy, known as Tol 1247-232, is a small (and possibly elliptical) galaxy located 652 million light-years away, in the direction of the southern Hydra constellation. This galaxy is one of just nine in the local Universe (and one of only three galaxies close to the Milky Way) that has been shown to emit Lyman continuum photons – a type of radiation in the ultraviolet band.
Back in May of 2016, the team spotted a single X-ray source coming from a star-forming region in this galaxy, using the Chandra X-ray observatory. Based on their observations, they determined that it was not caused by the formation of a new star. For one, new stars do not experience sudden changes in brightness, as this x-ray source did. In addition, the radiation emitted by new stars does not come in the form of a point-like source.
Instead, they determined that what they were seeing had to be the result of a very small object, which left only one likely explanation: a black hole. As Philip Kaaret, a professor in the UI Department of Physics and Astronomy and the lead author on the study, explained:
“The observations show the presence of very bright X-ray sources that are likely accreting black holes. It’s possible the black hole is creating winds that help the ionizing radiation from the stars escape. Thus, black holes may have helped make the universe transparent.”
Artist concept of matter swirling around a black hole. Credit: NASA/Dana Berry/SkyWorks Digital
However, this also raised the question of how a black hole could be emitting matter. This is something that astrophysicists have puzzled over for quite some time. Whereas all black holes have tendency to consume all that is in their path, a small number of supermassive black holes (SMBHs) have been found to have high-speed jets of charged particles streaming from their cores.
These SMBHs are what power Active Galactic Nuclei, which are compact, bright regions that has been observed at the centers of particularly massive galaxies. At present, no one is certain how these SMBHs manage to fire off jets of hot matter. But it has been theorized that they could be caused by the accelerated rotational energy of the black holes themselves.
In keeping with this, the team considered the possibility that accreting X-ray sources could explain the escape of matter from a black hole. In other words, as a black hole’s intense gravity pulls matter inward, the black hole responds by spinning faster. As the hole’s gravitational pull increases, the speed creates energy, which inevitably causes charged particles to be pushed out. As Kaaret explained:
“As matter falls into a black hole, it starts to spin and the rapid rotation pushes some fraction of the matter out. They’re producing these strong winds that could be opening an escape route for ultraviolet light. That could be what happened with the early galaxies.”
Depiction of the tidal disruption event in F01004-2237. The release of gravitational energy as the debris of the star is accreted by the black hole leads to a flare in the optical light of the galaxy. Credit and copyright: Mark Garlick
Taking this a step further, the team hypothesized that this could be what was responsible for light escaping the “Dark Ages”. Much like the jets of hot material being emitted by SMBHs today, similarly massive black holes in the early Universe could have sped up due to the accretion of matter, spewing out light from the cloudiness and allowing for the Universe to become a clear, bright place.
In the future, the UI team plans to study Tol 1247-232 in more detail and locate other nearby galaxies that are also emitting ultraviolet light. This will corroborate their theory that black holes could be responsible for the observed point source of high-energy X-rays. Combined with studies of the earliest periods of the Universe, it could also validate the theory that the “Dark Ages” ended thanks to the presence of black holes.
In addition to all that, engineers at the Jet Propulsion Laboratory in Pasadena, California, are busy preparing the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) Lander for its scheduled launch in 2018. Once deployed to Mars, the lander will reveal things about Mars’ interior geology and composition, shedding new light on the history of the Red Planet’s formation and evolution.
Originally scheduled for launch in 2016, the lander’s deployment was delayed due to the failure of a key component – a chamber that housed the Seismic Experiment for Interior Structure (SEIS). Having finished work on a new vacuum enclosure for this instrument, the technicians at Lockheed Martin Space Systems are back at work, assembling and testing the spacecraft in a clean room facility outside of Denver, Colorado.
This artist’s concept from August 2015 depicts NASA’s InSight Mars lander fully deployed for studying the deep interior of Mars. Credit: NASA/JPL-Caltech
As Stu Spath, the spacecraft program manager at Lockheed Martin, said in a NASA press statement:
“Our team resumed system-level integration and test activities last month. The lander is completed and instruments have been integrated onto it so that we can complete the final spacecraft testing including acoustics, instrument deployments and thermal balance tests.”
Beyond the exploration of Mars, the InSight mission is also expected to reveal information about how all terrestrial (i.e. rocky) planets in the Solar System formed over four billion years ago. Mars is an especially opportune target for this type of research since it has been relatively inactive for the past three billion years. However, when the planet was still young, it underwent geological processes that were analogous to Earth’s.
In other words, because the interior of Mars has been subject to less convection over the past three billion years, it has likely preserved evidence about its early geological history better than Earth has. InSight will study this preserved history through a series of instruments that will measure the planet’s seismology, heat loss, and the state and nature of its core.
Once it reaches Mars, the stationary lander will set down near Mars’ equator and deploy its two fold-out solar cells, which kind of resemble large fans. Within a few weeks of making its landing, it will use a robotic arm to place its two main instruments onto the Martian surface – the aforementioned Seismic Experiment for Interior Structure (SEIS) and the Heat Flow and Physical Properties Probe (HP³).
Artist’s impression of the interior of Mars. Credit: NASA/JPL
The SEIS instrument – which was developed by France’s National Center for Space Studies (CNES) in collaboration with NASA and several European scientific institutions – has a sensitivity comparable to the best research seismometers here on Earth. This instrument will record seismic waves from “marsquakes” and meteor impacts, which will reveal things about the planet’s interior layers.
The HP³ probe, supplied by the German Aerospace Center (DLR), will use a Polish-made self-hammering mechanism to bury itself to a depth of 3 meters (10 feet) or more. As it descends, the probe will extend a tether that contains temperature sensors every ~10 cm, which measure the temperature profile of the subsurface. Combined with surface measurements, the instrument will determine the amount of heat escaping from the planet’s interior.
A third experiment, known as Rotation and Interior Structure Experiment (RISE), will also come into play. This instrument will use the lander’s X-band radio link to conduct Doppler tracking of the lander’s location, which will also allow it to measure variations in Mars’ rotation axis. Since these variations are primarily related to the size and state of Mars’ core, this experiment will shed light on one of Mars’ greatest mysteries.
Thanks to multiple missions that have studies Mars’ surface and atmosphere, scientists now know that roughly 4.2 billions of years ago, Mars lost its magnetic field. Because of this, Mars’ atmosphere was stripped away by solar wind during the next 500 million years. It is believed that it was this process that allowed the planet to go from being a warmer, wetter environment in the past to the cold, desiccated and irradiated place it is today.
NASA’s InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. Credit: NASA/JPL-Caltech/Lockheed Martin
As such, determining the state of Mars’ core – i.e. whether it is solid or liquid, or differentiated between a solid outer core and liquid inner core – will allow scientists to gain a more comprehensive understanding of the planet’s geological history. It will also allow them to answer with a fair degree of certainty how and when Mars lost its magnetic field (and hence, its denser, warmer atmosphere).
The spacecraft’s science payload is also on track for next year’s launch. At present, the mission is scheduled to launch on May 5th, 2018, though this window could be moved to anytime within a five-week period. Regardless of what day it launches, mission planners indicate that the flight will reach Mars on November 26th, 2018 (the Monday after Thanksgiving).
As noted, the mission was originally planned to launch in March of 2016, but was canceled due to the presence of a leak in the special metal container designed to maintain near-vacuum conditions around the SEIS’s main sensors. Now that a redesigned vacuum vessel has been built and tested (and integrated with the SEIS) the spacecraft is ready for its new launch date.
Back in 2010, the InSight mission was selected from a total of 28 proposals, which were made as part of the twelfth round of selections for NASA’s Discovery Program. In contrast to New Frontiers or Flagship programs, Discovery missions are small-budget enterprises that aid in larger scientific pursuits. Along with two other finalists – the Titan Mare Explorer (TiME) and the Comet Hopper (CHopper) – InSight was awarded funding for further development.
Bruce Banerdt of NASA’s Jet Propulsion Laboratory is the Principle Investigator (PI) for the InSight mission.
Be sure to check out this video of the InSight mission (courtesy of NASA JPL) as well:
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
PLAYALINDA BEACH/KENNEDY SPACE CENTER, FL – Following a successful engine test firing of the Falcon 9 first stage late Thursday afternoon (Aug. 30), SpaceX is targeting a post Labor Day launch of the U.S. Air Force’s unmanned X-37B reusable mini-shuttle – a secretive technology testing spaceplane.
The brief but critical hold down engine test took place at 4:30 p.m. EDT (2030 GMT) Aug. 31 at Launch Complex 39A on NASA’s Kennedy Space Center – as witnessed live by myself and several spectators from nearby Playalinda Beach Causeway. See my photos herein.
Both SpaceX and the Air Force announced the target launch date after completion of the Aug. 31 engine test.
“Static fire test complete,” SpaceX confirmed via Twitter soon after completion of the test, “—targeting Falcon 9 launch of OTV-5 from Pad 39A at @NASAKennedy on Thursday, September 7.”
The routinely done static fire test and involves conducting a full launch dress rehearsal and countdown culminating with igniting all nine Merlin 1D first stage engines during a hold down test at the pad.
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
The Merlin’s generated a combined 1.7 million pounds of thrust and a huge exhaust plume billowing into the air from the north side flame trench during the test, which lasted several seconds.
The plume soon swirled overhead and dissipated about 10 minutes later. Ignition was accompanied by a loud roar we heard screaming out from the pad in all directions. A number of folks driving to and from Playalinda Beach had stopped to ask me what I was photographing prior to the test and stayed to witness the event.
The rocket will be lowered rolled back horizontally on the transporter erector into the SpaceX processing hangar and the spaceplane housed inside the payload fairing will be integrated on top. The full stack will then be rolled back out and erected at pad 39A.
The hold down test firing is carried out without the payload bolted on top inside the nose cone to keep it safe in the event of a catastrophic failure event such as occurred precisely 1 year ago – when a Falcon 9 blew up during fueling for similar engine test with the AMOS-6 satellite resulting in destruction of the rocket as well as the customers satellite hardware at pad 40.
The exact launch time had been a closely guarded secret – until this evening.
The X-37B launch is apparently lunchtime Thursday, September 7 at 12 PM – 12:01 PM, according to a Facebook post by the U.S. Air Force Space Command and the 45th Space Wing at Patrick Air Force Base, Fla., posted Friday evening.
“The Air Force Rapid Capabilities Office is undergoing final launch preparations for the fifth mission of the X-37B Orbital Test Vehicle [OTV],” the Secretary of the Air Force Public Affairs announced. “The OTV is scheduled to launch on Sept. 7, 2017, onboard a SpaceX Falcon 9 launch vehicle.
The USAF X-37B Orbital Test Vehicle is set for blastoff on Sept. 7, 2017, onboard a SpaceX Falcon 9 launch vehicle from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. Photo: Boeing/USAF
The X-37B will be launched for the fifth time on the OTV-5 mission atop a SpaceX Falcon 9 on Sept. 7 from Launch Complex 39A on the Kennedy Space Center Florida into low Earth orbit.
The Boeing-built X-37B is processed for flight at KSC using refurbished NASA space shuttle processing facilities now dedicated to the reusable mini-shuttle, also known as the Orbital Test Vehicle (OTV). It launches vertically like a satellite but lands horizontally like an airplane and functions as a reliable and reusable space test platform for the U.S. Air Force.
But in another first, the OTV-5 mission marks the first launch of an X-37B spaceplane by SpaceX.
All four prior OTV missions launched on the United Launch Alliance Atlas V and ended with runway landings in either California of Florida.
“The many firsts on this mission make the upcoming OTV launch a milestone for the program,” said Randy Walden, the director of the Air Force Rapid Capabilities Office.
“It is our goal to continue advancing the X-37B OTV so it can more fully support the growing space community.”
Blastoff of the X-37B spaceplane on United Launch Alliance (ULA) Atlas V rocket with the OTV-4 AFSPC-5 satellite for the U.S. Air Force at 11:05 a.m. EDT, May 20, 2015 from Space Launch Complex-41. Credit: Ken Kremer/kenkremer.com
After spending a record setting 718 days in orbit, the X-37B program completed its fourth mission with a runway landing back at KSC’s Shuttle Landing Facility on May 7, 2017. Overall OTV’s have spent a total of 2,085 days in orbit.
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
Playalinda Beach is located just 4 miles north of pad 39A and offers an excellent launch viewing location for the OTV-5 mission – if officials allow it to be open to the public.
The engine test comes at the end of a very busy August with a trio of Florida Space Coast launches plus a Total Solar ‘Eclipse Across America’ sandwiched in between.
Also noteworthy is that OTV-5 will be launched into a higher inclination orbit compared to the prior four, serve as a technology testbed for multiple research payloads and will also somehow deploy several small satellites or cubesats.
“The fifth OTV mission continues to advance the X-37B’s performance and flexibility as a space technology demonstrator and host platform for experimental payloads,” the USAF said in a statement.
“This mission carries small satellite ride shares and will demonstrate greater opportunities for rapid space access and on-orbit testing of emerging space technologies. Building upon the fourth mission and previous collaboration with experiment partners, this mission will host the Air Force Research Laboratory Advanced Structurally Embedded Thermal Spreader payload to test experimental electronics and oscillating heat pipe technologies in the long duration space environment.”
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
SpaceX will also attempt another land landing of the 156-foot-tall Falcon 9 first stage back at Landing Zone-1 (LZ-1) at the Cape.
The Falcon 9 first stage is equipped with a quartet of landing legs and grid fins to enable the rocket recycling plan.
“The fifth OTV mission will also be launched into, and landed from, a higher inclination orbit than prior missions to further expand the X-37B’s orbital envelope.”
The daylight first stage precision guided landing should offer spectators a thrilling up close view of the rocket reusability technology envisioned by SpaceX’s billionaire CEO Elon Musk to drastically slash the high costs of launching to space.
Ground landing of SpaceX Falcon 9 first stage at Landing Zone-1 (LZ-1) after SpaceX launched its 12th resupply mission to the International Space Station from NASA’s Kennedy Space Center in Florida from pad 39A at 12:31 p.m. EDT on Monday, Aug. 14, 2017. Credit: Ken Kremer/Kenkremer.com
The 11,000 pound (4990 kg) state-of -the art reusable OTV space plane is about a quarter the size of a NASA space shuttle. The vehicle measures 29 ft 3 in (8.9 m) in length with a wingspan of 14 ft 11 in (4.5 m).
The X-37B was originally developed by NASA but was transferred to the Defense Advanced Research Projects Agency (DARPA) in 2004.
Since then most but not all of the spaceplane’s goals have been shrouded in secrecy.
SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
The X-37B Orbital Test Vehicle taxiing on the flightline on March 30th, 2010, at the Astrotech facility in Titusville, Florida. Credit: USAFSpaceX Falcon 9 booster stands at Launch Complex 39A after successful Aug 31, 2017 hotfire engine as seen from nearby Playalinda Beach. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
Artist's impression of how the surface of a planet orbiting a red dwarf star may appear. The planet is in the habitable zone so liquid water exists. However, low levels of ultraviolet radiation from the star have prevented or severely impeded chemical processes thought to be required for life to emerge. This causes the planet to be devoid of life. Credit: M. Weiss/CfA
Ultraviolet light is what you might call a controversial type of radiation. On the one hand, overexposure can lead to sunburn, an increased risk of skin cancer, and damage to a person’s eyesight and immune system. On the other hand, it also has some tremendous health benefits, which includes promoting stress relief and stimulating the body’s natural production of vitamin D, seratonin, and melanin.
And according to a new study from a team from Harvard University and the Harvard-Smithsonian Center for Astrophysics (CfA), ultraviolet radiation may even have played a critical role in the emergence of life here on Earth. As such, determining how much UV radiation is produced by other types of stars could be one of the keys to finding evidence of life any planets that orbit them.
Artist’s impression of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri. The double star Alpha Centauri AB is visible to the upper right of Proxima itself. Credit: ESO
Recent studies have indicated that UV radiation may be necessary for the formation of ribonucleic acid (RNA), which is necessary for all forms of life as we know it. And given the rate at which rocky planets have been discovered around red dwarf stars of late (exampled include Proxima b, LHS 1140b, and the seven planets of the TRAPPIST-1 system), how much UV radiation red dwarfs give off could be central to determining exoplanet habitability.
“It would be like having a pile of wood and kindling and wanting to light a fire, but not having a match. Our research shows that the right amount of UV light might be one of the matches that gets life as we know it to ignite.”
For the sake of their study, the team created radiative transfer models of red dwarf stars. They then sought to determine if the UV environment on prebiotic Earth-analog planets which orbited them would be sufficient to stimulate the photoprocesses that would lead to the formation of RNA. From this, they calculated that planets orbiting M-dwarf stars would have access to 100–1000 times less bioactive UV radiation than a young Earth.
As a result, the chemistry that depends on UV light to turn chemical elements and prebiotic conditions into biological organisms would likely shut down. Alternately, the team estimated that even if this chemistry was able to proceed under a diminished level of UV radiation, it would operate at a much slower rate than it did on Earth billions of years ago.
Artist’s impression of the planet orbiting a red dwarf star. Credit: ESO/M. Kornmesser
As Robin Wordsworth – an assistant professor at the Harvard School of Engineering and Applied Science and a co-author on the study – explained, this is not necessarily bad news as far as questions of habitability go. “It may be a matter of finding the sweet spot,” he said. “There needs to be enough ultraviolet light to trigger the formation of life, but not so much that it erodes and removes the planet’s atmosphere.”
Previous studies have shown that even calm red dwarfs experience dramatic flares that periodically bombard their planets with bursts UV energy. While this was considered to be something hazardous, which could strip orbiting planets of their atmospheres and irradiate life, it is possible that such flares could compensate for the lower levels of UV being steadily produced by the star.
This news also comes on the heels of a study that indicated how the outer planets of the TRAPPIST-1 system (including the three located within its habitable zone) might still have plenty of water of their surfaces. Here too, the key was UV radiation, where the team responsible for the study monitored the TRAPPIST-1 planets for signs of hydrogen loss from their atmospheres (a sign of photodissociation).
This research also calls to mind a recent study led by Professor Avi Loeb, the Chair of the astronomy department at Harvard University, Director of the Institute for Theory and Computation, and also a member of the CfA. Titled, “Relative Likelihood for Life as a Function of Cosmic Time“, Loeb and his team concluded that red dwarf stars are the most likely to give rise to life because of their low mass and extreme longevity.
Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada
Compared to higher-mass stars that have shorter life spans, red dwarf stars are likely to remain in their main sequence for as long as six to twelve trillion years. Hence, red dwarf stars would certainly be around long enough to accommodate even a vastly decelerated rate of organic evolution. In this respect, this latest study might even be considered a possible resolution for the Fermi Paradox – Where are all the aliens? They’re still evolving!
But as Dimitar Sasselov – the Phillips Professor of Astronomy at Harvard, the Director of the Origins of Life Initiative and a co-author on the paper – indicated, there are still many unanswered questions:
“We still have a lot of work to do in the laboratory and elsewhere to determine how factors, including UV, play into the question of life. Also, we need to determine whether life can form at much lower UV levels than we experience here on Earth.”
As always, scientists are forced to work with a limited frame of reference when it comes to assessing the habitability of other planets. To our knowledge, life exists on only on planet (i.e. Earth), which naturally influences our understanding of where and under what conditions life can thrive. And despite ongoing research, the question of how life emerged on Earth is still something of a mystery.
If life should be found on a planet orbiting a red dwarf, or in extreme environments we thought were uninhabitable, it would suggest that life can emerge and evolve in conditions that are very different from those of Earth. In the coming years, next-generation missions like the James Webb Space Telescope are the Giant Magellan Telescope are expected to reveal more about distant stars and their systems of planets.
The payoff of this research is likely to include new insights into where life can emerge and the conditions under which it can thrive.
The constellation Crux, aka the Southern Cross. Credit: ESO/ Yuri Beletsky Nightscapes.
Welcome to another edition of Constellation Friday! Today, in honor of the late and great Tammy Plotner, we take a look at the “Southern Cross” – the Crux constellation. Enjoy!
In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of all the then-known 48 constellations. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively becoming astrological and astronomical canon until the early Modern Age.
One of these constellations is known as Crux, a small constellation located in the southern skies. Despite its size, it is one of the most well-known constellations in the southern hemisphere due to its distinctive cross-shape. Today, it has gone on to become one of the 88 modern constellations currently recognized by the International Astronomical Union (IAU).
Name and Meaning:
For the people of the Southern Hemisphere, the Crux constellation has a great deal of cultural significance. The Incas knew the constellation as Chakana (Quechua for “the stair”), and a stone image of the stars was found in Machu Picchu, Peru. To the Maori, the constellation was known as Te Punga, or “the anchor”, due to the important role it played in maritime navigation.
The “Emu in the Sky”, an important constellation recognized by the Aborigines of Australia. Credit: RSAA/ANU
To the Aborigines of Australia, the cross and the Coalsack Nebula together represented the head of the Emu in the Sky. This mythical bird is associated with several Aborigine creation myths and is one of the most important constellations in their astronomical traditions. Because of this significance, the Southern Cross is represented on the flags of Australia, Papua New Guinea, New Zealand Brazil, and Brazil.
The first recorded instance of Crux being named is believed to have occurred in 1455, when Venetian navigator Alvise Cadamosto made note of an asterism in the southern skies that he called carr dell’ostro (“southern chariot”). However, historians generally credit Portugese astronomer Joao Faras with the discovery, which occurred in 1500 when he spotted it from Brazil and named it “Las Guardas” (“the guards”).
By the late 16th century, Crux began to be depicted as a separate constellation on celestial globes and maps. In these and subsequent maps, the name Crux was used (Latin for “Cross”), referring to the constellation’s distinct shape.
History of Observation:
Crux was originally considered to be part of Centaurus, but as the precession of the equinoxes gradually lowered these stars below the European horizon, they were lost sight of, and so was the memory of these stars. At one time, around 1000 BCE, the stars of Crux were visible to the northern hemisphere, but by 400 CE they had slipped below the horizon for most populated areas.
The constellation Crux as it can be seen by the naked eye. Credit: Till Credner/AlltheSky.com
Even though it was originally plotted on Ptolemy’s Almagest, it first appeared as “Crux” on the charts of Petrus Plancius and Jodocus Hondius in 1598 and 1600 – both navigators. It is known that Amerigo Vespucci mapped the stars of Crux on his expedition to South America in 1501, and with good reason!
Two of the stars of Crux (Alpha and Gamma, Acrux and Gacrux respectively) are commonly used to mark due south. Following the line defined by the two stars for approximately 4.5 times the distance between them leads to a point close to the Southern Celestial Pole. A definite point needed for navigation! In 1920, Crux was included among the 88 modern constellations recognized by the IAU.
Notable Objects:
Of the major stars in Crux, Alpha Crucis (Acrux) is the brightest, and the 12th brightest star in the night sky. It is located approximately 320 light years away and is a multiple star system composed of Alpha-1 Crucis (a B class subgiant) and Alpha-2 Crucis (a B class dwarf). Both stars are very hot and their respective luminosities are 25,000 and 16,000 times that of the Sun.
Beta Crucis (Becrux, or Mimosa) is the second brightest star of the Southern Cross and the 20th brightest star in the night sky. It is approximately 350 light years distant, is classified as a Beta Cephei variable, and is a spectroscopic binary composed of two stars that are about 8 AU apart and orbit each other every five years. The name Mimosa refers to its color (blue-hued).
Gamma Crucis (Gacrux) is a red giant that is approximately 88 light years distant from Earth. It is the third brightest star in the Crux constellation and the 26th brightest star in the sky. Located about 400 light years distant from Earth, this binary star is composed of a M4 red dwarf star and a A3 white dwarf star.
Crux is also associated with several Deep Sky Objects, the most notable of which is the Coalsack Nebula. This object is easily seen as a dark patch in the southern region of the Milky Way (hence the name) and crosses into the neighboring constellations of Centaurus and Musca. It is located about 600 light years from Earth and is between 30 and 35 light years in radius. In Aboriginal astronomy, the nebula represents the head of the Emu.
Then there’s the Kappa Crucis Cluster (aka. the “Jewel Box” or “Herschel’s Jewel Box”), an open star cluster that is located approximately 6,440 light years from Earth. It contains roughly 100 stars and is one of the youngest clusters ever discovered (only 14 million years old). To the naked eye, the cluster appears like a star near Beta Crucis.
Finding Crux:
The constellation itself consists of four bright, main stars and 19 stars which have Bayer/Flamsteed designations. It is bordered by the constellations of Centaurus and Musca. At present, Crux is visible at latitudes between +20° and -90°. While it is fairly circumpolar for the southern hemisphere, it is best seen a culmination during the month of May.
The location of the Crux constellation. Credit: IAU
Now, let’s take out binoculars and examine its stars, started with Alpha Crucis, the “a” shape on our map. Its proper name is Acrux and it is the twelfth brightest star in the night sky. If you switch your binoculars out for a telescope, you’ll find that 321 light year distant Acrux is also a binary star, with components separated by about 4 arc seconds and around one half stellar magnitude difference in brightness.
The brighter of the two, A1 is itself a spectroscopic binary star – with a companion that orbits no further away than our own Earth, yet is around 14 times larger than our own Sun! Needless to say, there’s a very good chance this star may one day go supernova. While you’re there, take a look an addition 90 arc seconds away for a third star. While it may just be an optical companion to the Acrux system, it does share the same proper motion!
Back to binoculars an on to Beta Crucis – the “B” shape on the map. Mimosa is located about 353 light years away from our solar system and it is also a spectroscopic binary star. This magnificent blue/white giant star is tied at number 19 as one of the brightest stars in the sky, and if we could put it side by side with our Sun it would be 3000 times brighter. Mimosa is also a multiply-periodic Beta-Cephi type star, too, fluxing by about 1/10 of a magnitude in as little as hours. What’s going on? Inside Beta Crucis the iron content is only about half that of Sol and it’s nearing the end of its hydrogen-fusing stage. When the iron core develops? Watch out! It’s supernova time….
Now hang on to your binoculars and head north for Gamma Crucis, the “Y” shape on the map. Gacrux, is a red giant star approximately 88 light-years away from Earth. Did you notice its optical companion about 2 arc minutes away at an angle of 128 degrees from the main star? While the two look close together in the sky, the secondary star is actually 400 light years away! Gacrux shows its beautiful orange coloring to prove it has evolved off of the main sequence to become a red giant star, and it may even be evolving past the helium-burning stage.
The Coalsack Nebula and Kappa Crucis Cluster. Credit: A. Fujii
Move on now to Delta Crucis – the figure “8” on our map. Decrux is a red giant star located about 360 light years away from our vantage point. Delta Crucis is also Beta Cephei variable and changes its brightness just a tiny bit over a period of about an hour and 20 minutes. Another cool factoid about Delta Crucis is that it’s a fast rotator – spinning at a speed of at least 194 kilometers per second at the equator and making a full rotation in about 32 hours.
This massive star also produces a massive stellar wind, shooting off 1000 times more material than our own Sun every second of every day! Or try R Crucis… It’s also a Beta-Cephi type variable star, but it changes by nearly a full stellar magnitude in just a little over five days!
Keep your binoculars handy and head back to Beta and sweep south a degree and a half for the Kappa Crucis star cluster. This beautiful galactic cluster of stars commonly known as the Jewel Box (NGC 4755). After you see its glittering collection of multi-colored stars, you’ll understand how it got its name! It is one of the youngest clusters, perhaps only a few million years old.
Kappa Crucis is also right on the edge of a dark void in the sky called the “Coal Sack”. While you’re looking around, you’ll notice that there seem to be very few stars in this area. That’s because they are being blocked by a dark nebula! The Coal Sack is a large, dark dust cloud about 500 light years away and it’s blocking out the light from stars which lie beyond it. The few stars you do see are in front of the cloud and much nearer to the Earth.
The Jewel Box – the Kappa Crucis Cluster. Credit: ESO/NASA/ESA/Digitized Sky Survey 2/Jesús Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain)
Now it’s telescope time. Head to Alpha Crucis and slightly less than 2 degrees east for NGC4609. Also on the edge of the Coalsack, this large, fairly condensed open cluster contains about 40 members and they are well spread across the sky. The pattern somewhat resembles the constellation of Orion (in the imagination, of course!). Mark you observing notes for Caldwell 98. Next stop? Back to Delta and less than 3 degrees south/southwest for NGC4103, another open cluster on the edge of night. With a little bit of imagination, this grouping of stars could appear to look like a celestial water tower!
