Views of the rotating jet in comet 252P/LINEAR on April 4, 2016. Credit: Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)
These photos, taken on April 4, 2016 over the span of 4 1/2 hours, reveal a narrow, well-defined jet of dust ejected by the comet’s icy nucleus. With a diameter of only about a mile, the nucleus is too small for Hubble to see. The jet is illuminated by sunlight and changes direction like the hour hand on a clock as the comet spins on its axis. Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)
Remember 252P/LINEAR? This comet appeared low in the morning sky last month and for a short time grew bright enough to see with the naked eye from a dark site. 252P swept closest to Earth on March 21, passing just 3.3 million miles away or about 14 times the distance between our planet and the moon. Since then, it’s been gradually pulling away and fading though it remains bright enough to see in small telescope during late evening hours.
252P LINEAR looks like a big fuzzy ball in this photo taken on April 30. The comet is located in Ophiuchus and rises in the eastern sky at nightfall. At this scale, the jet shown in the Hubble photos is too tiny to see. See map below to find the comet yourself. Credit: Rolando Ligustri
While amateurs set their clocks to catch the comet before dawn, astronomers using NASA’s Hubble Space Telescope captured close-up photos of it two weeks after closest approach. The images reveal a narrow, well-defined jet of dust ejected by the comet’s fragile, icy nucleus spinning like a water jet from a rotating lawn sprinkler. These observations also represent the closest celestial object Hubble has observed other than the moon.
Want to get a good look at a comet’s tiny nucleus and its jets of vapor and dust? Get up close in the spaceship. This photo was taken by the European Space Agency’s Rosetta probe which has been orbiting Comet 67P/Churyumov-Gerasimenko since the fall of 2014. Credit: ESA
Sunlight warms a comet’s nucleus, vaporizing ices below the surface. In a confined space, the pressure of the vapor builds and builds until it finds a crack or weakness in the comet’s crust and blasts into space like water from a whale’s blowhole. Dust and other gases go along for the ride. Some of the dust drifts back down to coat the surface, some into space to be shaped by the pressure of sunlight into a dust tail.
This map shows the path — marked off every five nights at 11:30 p.m. CDT (4:30 UT) — of 252P/LINEAR along the border of Ophiuchus and Hercules through the end of June. Bright stars are labeled by Greek letter or number. Stars shown to magnitude 8.5. Click to enlarge. Diagram: Bob King, source: Chris Marriott’s SkyMap
You can still see 252P/LINEAR if you have a 4-inch or larger telescope. Right now it’s a little brighter than magnitude +9 as it slowly arcs along the border of Ophiuchus and Hercules. With the moon getting brighter and brighter as it fills toward full, tonight and tomorrow night will be best for viewing the comet. After that you’re best to wait till after the May 21st full moon when darkness returns to the evening sky. 252P will spend much of the next couple weeks near the 3rd magnitude star Kappa Ophiuchi, a convenient guidepost for aiming your telescope in the comet’s direction.
Get oriented on where to look for the comet by first using this map, which shows the sky facing southeast around 11-11:30 p.m. local daylight time in mid-May. Mars and Saturn make excellent guides to help you find Kappa Oph, located very near the comet. Diagram: Bob King , source: Stellarium
While you probably won’t see any jets in amateur telescopes, they’re there all the same and helped created this comet’s distinctive and large, fuzzy coma. Happy hunting!
The full sequence of images of the spinning jet in 252P/LINEAR seen by Hubble. Credit: NASA, ESA, and Z. Levay (STScI)
The large blue light is a lensing galaxy in the foreground, called SDP81, about 4 billion light years away. The red arcs are the distorted image of a more distant galaxy, about 12 billion light years away. By analyzing small distortions in the red, distant galaxy, astronomers have determined that a dwarf dark galaxy, represented by the white dot in the lower left, is bound to SDP81. The image is a composite from ALMA and the Hubble. Image: Y. Hezaveh, Stanford Univ./ALMA (NRAO/ESO/NAOJ)/NASA/ESA Hubble Space Telescope
Everybody knows that galaxies are enormous collections of stars. A single galaxy can contain hundreds of billions of them. But there is a type of galaxy that has no stars. That’s right: zero stars.
These galaxies are called Dark Galaxies, or Dark Matter Galaxies. And rather than consisting of stars, they consist mostly of Dark Matter. Theory predicts that there should be many of these Dwarf Dark Galaxies in the halo around ‘regular’ galaxies, but finding them has been difficult.
Now, in a new paper to be published in the Astrophysical Journal, Yashar Hezaveh at Stanford University in California, and his team of colleagues, announce the discovery of one such object. The team used enhanced capabilities of the Atacamas Large Millimeter Array to examine an Einstein ring, so named because Einstein’s Theory of General Relativity predicted the phenomenon long before one was observed.
An Einstein Ring is when the massive gravity of a close object distorts the light from a much more distant object. They operate much like the lens in a telescope, or even a pair of eye-glasses. The mass of the glass in the lens directs incoming light in such a way that distant objects are enlarged.
Einstein Rings and gravitational lensing allow astronomers to study extremely distant objects, by looking at them through a lens of gravity. But they also allow astronomers to learn more about the galaxy that is acting as the lens, which is what happened in this case.
If a glass lens had tiny water spots on it, those spots would add a tiny amount of distortion to the image. That’s what happened in this case, except rather than microscopic water drops on a lens, the distortions were caused by tiny Dwarf Galaxies consisting of Dark Matter. “We can find these invisible objects in the same way that you can see rain droplets on a window. You know they are there because they distort the image of the background objects,” explained Hezaveh. The difference is that water distorts light by refraction, whereas matter distorts light by gravity.
As the ALMA facility increased its resolution, astronomers studied different astronomical objects to test its capabilities. One of these objects was SDP81, the gravitational lens in the above image. As they examined the more distant galaxy being lensed by SDP81, they discovered smaller distortions in the ring of the distant galaxy. Hezaveh and his team conclude that these distortions signal the presence of a Dwarf Dark Galaxy.
But why does this all matter? Because there is a problem in the Universe, or at least in our understanding of it; a problem of missing mass.
Our understanding of the formation of the structure of the Universe is pretty solid, at least in the larger scale. Predictions based on this model agree with observations of the Cosmic Microwave Background (CMB) and galaxy clustering. But our understanding breaks down somewhat when it comes to the smaller scale structure of the Universe.
One example of our lack of understanding in this area is what’s known as the Missing Satellite Problem. Theory predicts that there should be a large population of what are called sub-halo objects in the halo of dark matter surrounding galaxies. These objects can range from things as large as the Magellanic Clouds down to much smaller objects. In observations of the Local Group, there is a pronounced deficit of these objects, to the tune of a factor of 10, when compared to theoretical predictions.
Because we haven’t found them, one of two things needs to happen: either we get better at finding them, or we modify our theory. But it seems a little too soon to modify our theories of the structure of the Universe because we haven’t found something that, by its very nature, is hard to find. That’s why this announcement is so important.
The observation and identification of one of these Dwarf Dark Galaxies should open the door to more. Once more are found, we can start to build a model of their population and distribution. So if in the future more of these Dwarf Dark Galaxies are found, it will gradually confirm our over-arching understanding of the formation and structure of the Universe. And it’ll mean we’re on the right track when it comes to understanding Dark Matter’s role in the Universe. If we can’t find them, and the one bound to the halo of SDP81 turns out to be an anomaly, then it’s back to the drawing board, theoretically.
It took a lot of horsepower to detect the Dwarf Dark Galaxy bound to SDP81. Einstein Rings like SDP81 have to have enormous mass in order to exert a gravitational lensing effect, while Dwarf Dark Galaxies are tiny in comparison. It’s a classic ‘needle in a haystack’ problem, and Hezaveh and his team needed massive computing power to analyze the data from ALMA.
ALMA will consist of 66 individual antennae like these when it is complete. The facility is located in the Atacama Desert in Chile, at 5,000 meters above sea level. Credit: ALMA (ESO / NAOJ / NRAO)
ALMA, and the methodology developed by Hezaveh and team will hopefully shed more light on Dwarf Dark Galaxies in the future. The team thinks that ALMA has great potential to discover more of these halo objects, which should in turn improve our understanding of the structure of the Universe. As they say in the conclusion of their paper, “… ALMA observations have the potential to significantly advance our understanding of the abundance of dark matter substructure.”
In this March 2002 image, John Grunsfeld, former astronaut and associate administrator of NASA's Science Mission Directorate, is shown in space shuttle Columbia's cargo bay during the STS-109 Hubble servicing mission. Credits: NASA
In this March 2002 image, John Grunsfeld, former astronaut and associate administrator of NASA’s Science Mission Directorate, is shown in space shuttle Columbia’s cargo bay during the STS-109 Hubble servicing mission. Credits: NASA
Five time space shuttle astronaut and current NASA science chief John Grunsfeld – best known as the ‘Hubble Hugger’ for three critical and dramatic servicing and upgrade missions to the iconic Hubble Space Telescope – his decided to retire from the space agency he faithfully served since being selected as an astronaut in 1992.
“John Grunsfeld will retire from NASA April 30, capping nearly four decades of science and exploration with the agency. His tenure includes serving as astronaut, chief scientist, and head of NASA’s Earth and space science activities,” NASA announced.
Indeed, Grunsfeld was the last human to touch the telescope during the STS-125 servicing mission in 2009 when he served as lead spacewalker.
The STS-125 mission successfully upgraded the observatory to the apex of its scientific capability during five spacewalks by four astronauts and extended the life of the aging telescope for many years. Hubble remains fully operable to this day!
In April 2015, Hubble celebrated 25 years of operations, vastly outperforming its planned lifetime of 15 years.
“Hubble has given us 25 years of great service. Hopefully we’ll get another 5 to 10 years of unraveling the mysteries of the Universe,” Grunsfeld told me during a recent interview at NASA Goddard.
Astronaut John Grunsfeld performs work on the Hubble Space Telescope on the first of five STS-125 spacewalks. Credit: NASA
In his most recent assignment, Grunsfeld was NASA’s Science Chief working as the Associate Administrator for the Science Mission Directorate (SMD) at NASA Headquarters in Washington, D.C. since January 2012.
“John leaves an extraordinary legacy of success that will forever remain a part of our nation’s historic science and exploration achievements,” said NASA Administrator Charlie Bolden, in a statement.
“Widely known as the ‘Hubble Repairman,’ it was an honor to serve with him in the astronaut corps and watch him lead NASA’s science portfolio during a time of remarkable discovery. These are discoveries that have rewritten science textbooks and inspired the next generation of space explorers.”
Grunsfeld was inducted into the U.S. Astronaut Hall of Fame in 2015.
He received his PhD in physics in 1988 and conducted extensive research as an astronomer in the fields of x-ray and gamma ray astronomy and high-energy cosmic ray studies.
Crew of STS-125, including John Grunsfeld, center, during walkout to Astrovan ahead of launch on May 11, 2009, from the Kennedy Space Center in Florida on final mission to service NASA’s Hubble Space Telescope. Credit: Ken Kremer – kenkremer.com
NASA said that Grunsfeld’s deputy Geoff Yoder will serve as SMD acting associate administrator until a successor is named.
“After exploring strange new worlds and seeking out new life in the universe, I can now boldly go where I’ve rarely gone before – home,” said Grunsfeld.
“I’m grateful to have had this extraordinary opportunity to lead NASA science, and know that the agency is well-positioned to make the next giant leaps in exploration and discovery.”
During his tenure as science chief leading NASA’s Science Mission Directorate Grunsfeld was responsible for managing over 100 NASA science missions including the Mars orbital and surface assets like the Curiosity and Opportunity Mars rovers, New Horizons at Pluto, MESSENGER, upcoming Mars 2020 rover and OSIRIS-Rex as well as Earth science missions like the Deep Space Climate Observatory, Orbiting Carbon Observatory-2, and Global Precipitation Measurement spacecraft -which resulted numerous groundbreaking science, findings and discoveries.
NASA Associate Administrator for the Science Mission Directorate John Grunsfeld, left, New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO, second from left, New Horizons Mission Operations Manager Alice Bowman of the Johns Hopkins University Applied Physics Laboratory (APL), second from right, and New Horizons Project Manager Glen Fountain of APL, right, are seen at the conclusion of a press conference after the team received confirmation from the spacecraft that it has completed the flyby of Pluto, Tuesday, July 14, 2015 at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. Credit: Ken Kremer/kenkremer.com
Dr. Grunsfeld is a veteran of five spaceflights: STS-67 (1995), STS-81 (1997), STS-103 (1999) STS-109 (2002) and STS-125 (2009), during which time he logged more than 58 days in space, including 58 hours and 30 minutes of EVA in 8 spacewalks.
He briefly retired from NASA in December 2009 to serve as Deputy Director of the Space Telescope Science Institute, in Baltimore, Maryland. He then returned to NASA in January 2012 to serve as SMD head for over four years until now.
NASA Science chief and astronaut John Grunsfeld discusses James Webb Space Telescope project at NASA Goddard Space Flight Center in Maryland. Credit: Ken Kremer/kenkremer.com
From his NASA bio, here is a summary of John Grunsfeld’s space flight experience during five shuttle flights:
STS-67/Astro-2 Endeavour (March 2 to March 18, 1995) launched from Kennedy Space Center, Florida, and landed at Edwards Air Force Base, California. It was the second flight of the Astro observatory, a unique complement of three ultraviolet telescopes. During this record-setting 16-day mission, the crew conducted observations around the clock to study the far ultraviolet spectra of faint astronomical objects and the polarization of ultraviolet light coming from hot stars and distant galaxies. Mission duration was 399 hours and 9 minutes.
STS-81 Atlantis (January 12 to January 22, 1997) was a 10-day mission, the fifth to dock with Russia’s Space Station Mir and the second to exchange U.S. astronauts. The mission also carried the Spacehab double module, providing additional middeck locker space for secondary experiments. In 5 days of docked operations, more than 3 tons of food, water, experiment equipment and samples were moved back and forth between the two spacecraft. Grunsfeld served as the flight engineer on this flight. Following 160 orbits of the Earth, the STS-81 mission concluded with a landing on Kennedy Space Center’s Runway 33, ending a 3.9-million-mile journey. Mission duration was 244 hours and 56 minutes.
STS-103 Discovery (December 19 to December 27, 1999) was an 8-day mission, during which the crew successfully installed new gyroscopes and scientific instruments and upgraded systems on the Hubble Space Telescope (HST). Enhancing HST scientific capabilities required three spacewalks (EVAs). Grunsfeld performed two spacewalks, totaling 16 hours and 23 minutes. The STS-103 mission was accomplished in 120 Earth orbits, traveling 3.2 million miles in 191 hours and 11 minutes.
STS-109 Columbia (March 1 to March 12, 2002) was the fourth HST servicing mission. The crew of STS-109 successfully upgraded the HST, installing a new digital camera, a cooling system for the infrared camera, new solar arrays and a new power system. HST servicing and upgrades were accomplished by four crewmembers during a total of five EVAs in 5 consecutive days. As Payload Commander on STS-109, Grunsfeld was in charge of the spacewalking activities and the Hubble payload. He also performed three spacewalks totaling 21 hours and 9 minutes, including the installation of the new Power Control Unit. STS-109 orbited the Earth 165 times and covered 3.9 million miles in over 262 hours.
STS-125 Atlantis (May 11 to May 24, 2009) was the fifth and final Hubble servicing mission. After 19 years in orbit, the telescope received a major renovation that included the installation of a new wide-field camera, a new ultraviolet telescope, new batteries, a guidance sensor, gyroscopes and other repairs. Grunsfeld served as the lead spacewalker in charge of the spacewalking and Hubble activities. He performed three of the five spacewalks on this flight, totaling 20 hours and 58 minutes. For the first time while in orbit, two scientific instruments were surgically repaired in the telescope. The STS-125 mission was accomplished in 12 days, 21 hours, 37 minutes and 09 seconds, traveling 5,276,000 miles in 197 Earth orbits.
Launch of Space Shuttle Atlantis on STS-125 and the final servicing mission to the Hubble Space Telescope on May 11, 2009 from Launch Complex-39A at the Kennedy Space Center in Florida. Credit: Ken Kremer – kenkremer.com
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Learn more about Hubble, NASA Mars rovers, Orion, SLS, ISS, Orbital ATK, ULA, SpaceX, Boeing, Space Taxis, NASA missions and more at Ken’s upcoming outreach events:
Apr 9/10: “NASA and the Road to Mars Human Spaceflight programs” and “Curiosity explores Mars” at NEAF (NorthEast Astronomy and Space Forum), 9 AM to 5 PM, Suffern, NY, Rockland Community College and Rockland Astronomy Club – http://rocklandastronomy.com/neaf.html
Apr 12: Hosting Dr. Jim Green, NASA, Director Planetary Science, for a Planetary sciences talk about “Ceres, Pluto and Planet X” at Princeton University; 7:30 PM, Amateur Astronomers Assoc of Princeton, Peyton Hall, Princeton, NJ – http://www.princetonastronomy.org/
Apr 17: “NASA and the Road to Mars Human Spaceflight programs”- 1:30 PM at Washington Crossing State Park, Nature Center, Titusville, NJ – http://www.state.nj.us/dep/parksandforests/parks/washcros.html
NASA Administrator Charles Bolden and science chief Astronaut John Grunsfeld discuss NASA’s human spaceflight initiatives backdropped by the service module for the Orion crew capsule being assembled at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
China has plans to build a new space telescope which should outperform Hubble. According to the Chinese English Language Daily, the new telescope will be similar to Hubble, but will have a field of view that is 300 times larger. The new telescope, which has not been named yet, will have the ability to dock with China’s modular space station, the Tiangong.
The China National Space Administration has come up with a solution to a problem that dogged the Hubble Telescope. Whenever the Hubble needed repairs or maintenance, a shuttle mission had to be planned so astronauts could service it. China will avoid this problem with its innovative solution. The Chinese telescope will keep its distance from the Tiangong, but if repairs or maintenance are needed, it can dock with Tiangong.
No date has been given for the launch of this new telescope, but its plans must be intertwined with plans for the modular Tiangong space station. Tiangong-1 was launched in 2011 and has served as a crewed laboratory and a technological test-bed. The Tiangong-2, which has room for a crew of 3 and life support for twenty days, is expected to be launched sometime in 2016. The Tiangong-3 will provide life support for 3 people for 40 days and will expand China’s capabilities in space. It’s not expected to launch until sometime in the 2020’s, so the space telescope will likely follow its launch.
An artist’s rendering of the Tiangong-1 module, China’s space station, which was launched to space in September, 2011. To the right is a Shenzhou spacecraft, preparing to dock with the module. Image Credit: CNSA
The telescope, according to the People’s Daily Online, will take 10 years to capture images of 40% of space, with a precision equal to Hubble’s. China hopes this data will allow it to make breakthroughs in the understanding of the origin, development, and evolution of the universe.
This all sounds great, but there’s a shortage of facts. When other countries and space agencies announce projects like this, they give dates and timelines, and details about the types of cameras and sensors. They talk about exactly what it is they plan to study and what results they hope to achieve. It’s difficult to say what level of detail has gone into the planning for this space telescope. It’s also difficult to say how the ‘scope will dock with the space station.
It may be that China is nervous about spying and doesn’t want to reveal any technical detail. Or it may be that China likes announcing things that make it look technologically advanced. (China is in a space race with India, and likes to boast of its prowess.) In any case, they’ve been talking about a space telescope for many years now. But a little more information would be nice.
Come on China. Give us more info. We’re not spies. We promise.
A photo of the full moon, taken from Apollo 11 on its way home to Earth, from about 18,520 km (10,000 nm) away. Credit: NASA
People often criticize the amount of money spent on space exploration. Sometimes it’s well-meaning friends and family who say that that money is wasted, and would be better spent on solving problems here on Earth. In fact, that’s a whole cultural meme. You see it played out over and over in the comments section whenever mainstream media covers a space story.
While solving problems here on Earth is noble, and the right thing to do, it’s worth pointing out that the premier space exploration body on Earth, NASA, actually has a tiny budget. When you compare NASA’s budget to what people spend on cigarettes, NASA looks pretty good.
Ignoring for the moment the fact that we don’t know how to solve all the problems here on Earth, let’s look at NASA’s budget over the years, and compare it to something that is truly a waste of money: cigarettes and tobacco.
NASA is over 50 years old. In its first year, its budget was $89 million. (That’s about $732 million in today’s dollars.) In that same year, Americans spent about $6 billion on cigarettes and tobacco.
Buzz Aldrin on the Moon. Image Credit: NASA
From 1969 to 1972, NASA’s Apollo Program landed 12 men on the Moon. They won the Space Race and established a moment that will echo through the ages, no matter what else humanity does: the first human footsteps anywhere other than Earth. In those four years, NASA’s combined budget was $14.8 billion. In that same time period, Americans spent over twice as much—$32 billion—on smoking.
STS-1 Columbia on the launch pad. Image Credit: NASA
In 1981, NASA launched its first space shuttle, the Columbia (STS-1). NASA’s budget that year was $5.5 billion. That same year, the American population spent about $17.4 billion on tobacco. That’s three times NASA’s budget. How many more shuttle flights could there have been? How much more science?
The Hubble Space Telescope in 1997, after its first servicing mission. It’s about 552 km (343m) above Earth. Image: NASA
In 1990, NASA launched the Hubble Space Telescope into Low Earth Orbit (LEO.) The Hubble has been called the most successful science project in history, and Universe Today readers probably don’t need to be told why. The Hubble is responsible for a laundry list of discoveries and observations, and has engaged millions of people around the world in space science and discovery. In that year, NASA had a budget of $12.4 billion. And smoking? In 1990, Americans smoked their way through $26.5 billion of tobacco.
MSL Curiosity selfie on the surface of Mars. Image: NASA/JPL/Cal-Tech.
In 2012, NASA had a budget of $16.8 billion. In that year, NASA successfully landed the Mars Science Laboratory (MSL) Curiosity on Mars, at a cost of $2.5 billion. Also that year, American lungs processed $44 billion worth of tobacco. That’s the equivalent of 17 Curiosity rovers!
There was an enormous scientific debate around where Curiosity should land, in order to maximize the science. Scientific teams competed to have their site chosen, and eventually the Gale Crater was selected as the most promising site. Gale is a meteor crater, and was chosen because it shows signs of running water, as well as evidence of layered geology including clays and minerals.
Sunrise at Gale Crater on Mars. Gale is at center top with the mound in the middle, called Mt. Sharp (Aeolis Mons.)
But other equally tantalizing sites were in contention, including Holden Crater, where a massive and catastrophic flood took place, and where ancient sediments lie exposed on the floor of the crater, ready for study. Or Mawrth Vallis, another site that suffered a massive flood, which exposed layers of clay minerals formed in the presence of water. With the money spent on tobacco in 2012 ($44 billion!) we could have had a top ten list of landing sites on Mars, and put a rover at each one.
Think of all that science.
One of the JWST’s gold-coated mirrors. Not even launched yet, and the golden mirrors are already iconic. Image Credit: NASA/Drew Noel
NASA’s budget is always a source of controversy, and that’s certainly true of another of NASA’s big projects: The James Webb Space Telescope (JWST.) Space enthusiasts are eagerly awaiting the launch of the JWST, planned for October 2018. The JWST will take up residence at the second Lagrange Point (L2,) where it will spend 5-10 years studying the formation of galaxies, stars, and planetary systems from the Big Bang until now. It will also investigate the potential for life in other solar systems.
The L2 (Lagrange 2) point in space. Image Credit: NASA
Initially the JWST’s cost was set at $1.6 billion and it was supposed to launch in 2011. But now it’s set for October 2018, and its cost has grown to $8.8 billion. It sounds outrageous, almost $9 billion for a space telescope, and Congress considered scrapping the entire project. But what’s even more outrageous is that Americans are projected to spend over $50 billion on tobacco in 2018.
When people in the future look back at NASA and what it was able to accomplish in the latter half of the 20th century and the beginning of the 21st century, they’ll think two things: First, they’ll think how amazing it was that NASA did what it did. The Moon landings, the Shuttle program, the Hubble, Curiosity, and the James Webb.
Then, they’ll be saddened by how much more could’ve been done collectively, if so much money hadn’t been wasted on something as deadly as smoking.
This new image from the largest planet in the Solar System, Jupiter, was made during the Outer Planet Atmospheres Legacy (OPAL) programme. The images from this programme make it possible to determine the speeds of Jupiter’s winds, to identify different phenomena in its atmosphere and to track changes in its most famous features.
The map shown was observed on 19 January 2015, from 2:00 UT to 12:30 UT.
Credit:
NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), and G. Orton (JPL-Caltech)
Jupiter global map created from still images from the Hubble Space Telescope
It’s been widely reported, including at Universe Today, that the apple of Jupiter’s eye, the iconic Great Red Spot (GRS), has been shrinking for decades. Even the rate of shrinkage has been steadily increasing.
Back in the late 1800s you could squeeze three Earths inside the GRS. Those were the days. Last May it measured just 10,250 miles (16,496 km) across, big enough for only 1.3 of us.
And while new photos from the Hubble Space Telescope show that Jupiter’s swollen red eye has shrunk an additional 150 miles (240 km) since 2014, the good news is that the rate of shrinkage appears to be well, shrinking. The contraction of the GRS has been studied closely since the 1930s; even as recently as 1979, the Voyager spacecraft measured it at 14,500 miles (23,335 km) across. But the alarm sounded in 2012, when amateur astronomers discovered sudden increase in the rate of 580 miles (933 km) a year along with a shift in shape from oval to roughly circular.
For the moment, it appears that the GRS is holding steady, making for an even more interesting Jupiter observing season than usual. Already, the big planet dominates the eastern sky along with Venus on October mornings. Consider looking for changes in the Spot yourself in the coming months. A 6-inch or larger scope and determination are all you need.
Hubble photos of the Great Red Spot taken on a first rotation (left frames) and 10 hours later (right frames) show the counterclockwise rotation of the newly-discovered filament or wisp inside the GRS. Credit: NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), and G. Orton (JPL-Caltech)
New imagery from the Hubble OPAL program also shows a curious wisp at the center of the Great Red Spot spanning almost the entire width of the hurricane-like vortex. This filamentary streamer rotates and twists throughout the 10-hour span of the Great Red Spot image sequence, drawn out by winds that are blowing at 335 mph (540 km/hr). Color-wise, the GRS remains orange, not red. Currently, the reddest features on the planet are the North Equatorial Belt and the occasional dark, oval “barges” (cyclonic storms) in the northern hemisphere.
The newly-found waves in Jupiter’s atmosphere are located in regions where cyclones and anticyclones are common. They look like dark eyelashes. A cyclone is a storm or system of winds that rotates around an area of low pressure. Anticyclones spin around areas of high pressure. Credit: NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), and G. Orton (JPL-Caltech)
That’s not all. The photos uncovered a rare wave structure just north of Jupiter’s equator that’s only been seen once before and with difficulty by the Voyager 2 spacecraft in 1979. The scientists, whose findings are described in this just-published Astrophysical Journal paper, say it resembles an earthly atmospheric feature called a baroclinic wave,a large-scale meandering of the jet stream associated with developing storms.
Hubble view of Jupiter’s baroclinic waves on January 19, 2015 (top) and our only other view of them photographed by Voyager 2 in 1979. Credit: NASA, ESA, A. Simon (GSFC), M. Wong (UC Berkeley), and G. Orton (JPL-Caltech)
Jupiter’s “current wave” riffles across a region rich with cyclonic and anticyclonic storms. The wave may originate in a clear layer beneath Jupiter’s clouds, only becoming visible when it propagates up into the cloud deck, according to the researchers. While it’s thought to be connected to storm formation in the Jovian atmosphere, it’s a mystery why the wave hasn’t been observed more often.
The OPAL program focuses on long-term observation of the atmospheres of Jupiter, Uranus and Neptune until the end of the Saturn Cassini Mission and all four planets afterwords. We have to keep watch from Earth as no missions to Saturn and beyond are expected for quite some time. To date, Neptune and Uranus have already been observed with photos to appear (hopefully) soon in a public archive.
Artist’s conception of proposed proposed High-Definition Space Telescope, which would have a giant segmented mirror and unprecedented resolution at optical and UV wavelengths. (NASA/GSFC)
Decades after its momentous launch, the ever popular Hubble Space Telescope merrily continues its trajectory in low-earth orbit, and it still enables cutting-edge science. Astronomers utilized Hubble and its instruments over the years to obtain iconic images of the Crab Nebula, the Sombrero Galaxy, the Ultra Deep Field, and many others that captured the public imagination. Eventually its mission will end, and people need to plan for the next telescope and the next next telescope. But what kinds of space exploration do scientists want to engage in 20 years from now? What technologies will they need to make it happen?
A consortium of physicists and astronomers attempt to answer these questions as they put forward and promote their bold proposal for a giant high-resolution telescope for the next generation, which would observe numerous planets, stars, galaxies and the distant universe in stunning detail. In addition to encouraging support for scientific discoveries that could be made, the telescope’s advocates also must investigate the potential technical challenges involved in constructing and launching it. An event organized at a SPIE optics and photonics conference in San Diego, California on Tuesday served as another step in this long-term process.
The Association of Universities for Research in Astronomy (AURA), an influential organization of astronomers and physicists from 39 mostly US-based institutions, which operates telescopes and observatories for NASA and the National Science Foundation, laid out its proposal of a multi-wavelength High-Definition Space Telescope (HDST) in a new report last month. Julianne Dalcanton of the University of Washington and Sara Seager of the Massachusetts Institute of Technology—veteran astronomers with impressive knowledge and experience with galactic and planetary science—led the committee who researched and wrote the 172-page document.
“It’s the science community staking out a vision for what’s the next thing to do,” said Phil Stahl, former SPIE president and senior physicist at NASA’s Marshall Space Flight Center. Speaking at the optics and photonics conference about the telescope provided “an opportunity to speak to the people who will be building it,” as many of the audience work on instrumentation.
As the HDST’s name suggests, its 12-meter wide segmented mirror would give it much higher resolution than any current or upcoming telescopes, allowing astronomers to focus on many Earth-like “exoplanets” orbiting stars outside our solar system up to 100 light-years away, resolve stars even in the Andromeda Galaxy, and image faraway galaxies dating back 10 billion years of cosmic time into our universe’s past. The 24x increased sharpness compared to Hubble and the upcoming James Webb Space Telescope is similar to the dramatic improvement of an UltraHD TV over a standard television, according to Marc Postman, an astronomer at the Space Telescope Science Institute.
A simulated spiral galaxy as viewed by Hubble and the proposed High Definition Space Telescope at a lookback time of approximately 10 billion years. Image credit: D. Ceverino, C. Moody, G. Snyder, and Z. Levay (STScI)
In particular, “exoplanets are the main science driver for the HDST,” said Seager. “Are there other planets like Earth, and are there signs of life on them?” Her and her colleagues’ excitement came through as she explained that, if the telescope comes to fruition, they predict it would find dozens, if not hundreds, of Earth-like planets in the habitable zone. They would look for evidence of oxygen and water vapor as well, transforming astronomers’ knowledge of such planets, currently limited to only 1 or 2 candidates detected by the Kepler telescope.
The Hubble telescope required 20 years of planning, technological development, and budget allocations before it was launched in 1990. Planning for NASA’s James Webb Space Telescope (JWST), which was also first proposed by AURA, began not long afterward. Rome wasn’t built in a day, but many years of preparations and research will come to fruition as it is set to launch in 2018. Its scientists and engineers hope that, like Hubble, it will produce spectacular images with its infrared cameras, become a household name, and expand our understanding of the universe.
Nevertheless, James Webb has been plagued by a ballooning budget and numerous delays, and Congress nearly terminated it in 2011. The telescope proved controversial even among some astronomers and space exploration advocates. As scientists develop the next generation of telescopes, JWST remains the multi-ton multi-billion-dollar elephant in the room. David Redding of Jet Propulsion Laboratory was quick to point out that, “for Hubble, almost every technology had to be invented!” For the proposed HDST, the task appears less daunting.
Nonetheless, scientists have technological challenges and difficult questions to look forward to. For example, they must choose among multiple competing designs and consider different methods for getting the telescope into space, possibly utilizing the Space Launch System (SLS). They also expect to leverage research on JWST’s sunshield, which will be necessary to keep the proposed telescope at an extremely stable temperature, and on its detectors, when developing optimized gigapixel-class cameras. Vibrational stability on the order of one trillionth of a meter will present an additional challenge for them.
If the astronomical community comes on board and prioritizes this project for the next decade, then it likely would be designed and constructed in the 2020s and then launched in the 2030s. In the meantime, they will need major investments of funding, research and development. According to Seager, it will certainly be worth it “to observe the whole universe at 100 parsec-scale resolution” and “discover dozens of Earths.” Adding emphasis, “that’s the killer app,” Postman concluded.
Activity within the jet from NGC 3852 imaged by Hubble. Credit: NASA, ESA, and E. Meyer (STScI).
Even the Empire’s planet-blasting battle station has nothing compared to the immense energy being fired from the heart of NGC 3862, a supermassive black hole-harboring elliptical galaxy located 300 million light-years away.
And while jets of high-energy plasma coming from active galactic nuclei have been imaged before, for the first time activity within a jet has been observed in optical wavelengths, revealing a quite “forceful” collision of ejected material at near light speeds.
Using archived image data acquired by Hubble in 1994, 1996, and 2002 combined with new high-resolution images acquired in 2014, Eileen Meyer at the Space Telescope Science Institute (STScI) in Baltimore, Maryland identified movement in visible clumps of plasma within the jet emitted from the nucleus of NGC 3862 (aka 3C 264). One of the outwardly-moving larger clumps could be seen gaining on a slower, smaller one in front of it and the two eventually collide, creating a shockwave that brightens the resulting merged mass dramatically.
Such a collision has never been witnessed before, and certainly not thousands of light-years out from the central supermassive black hole.
Close-up image of the jet as seen in 2014. Credit: NASA, ESA, and E. Meyer (STScI).
“Something like this has never been seen before in an extragalactic jet,” Meyer said. “This will allow us a very rare opportunity to see how the kinetic energy of the collision is dissipated into radiation.”
Jets like this are created when infalling material around an active (that is, “feeding”) supermassive black hole gets caught up in its powerful spinning and twisting magnetic fields. This accelerates the material even further and, rather than permitting it to descend down past the black hole’s event horizon, results in it getting shot out into space at velocities close to the speed of light.
When material approaches the black hole in even amounts the jets are fairly consistent. But if the inflow is uneven, the jets can consist of clumps or knots traveling outward at different speeds.
Because of the motion of the galaxy itself related to our own, the speed of the clumps can appear to actually move faster than the speed of light, especially when – as seen in NGC 3862 – a large clump has already paved the way within the jet. In reality the light speed limit has not been broken, but the apparent superluminal motion so far from the SMBH indicates that the material was ejected extremely energetically.
It’s expected that the combined clusters of material will continue to brighten over the next several decades.
You can see a video of the observations below, and watch a Google+ Hangout with Hubble team members about these observations here.
