Universe Today

June 18, 2013December 23, 2015 by Jason Major

Venus’ Winds Are Mysteriously Speeding Up

Over the past six years wind speeds in Venus' atmosphere have been steadily rising (ESA)

High-altitude winds on neighboring Venus have long been known to be quite speedy, whipping sulfuric-acid-laden clouds around the superheated planet at speeds well over 300 km/h (180 mph). And after over six years collecting data from orbit, ESA’s Venus Express has found that the winds there are steadily getting faster… and scientists really don’t know why.

Cloud structures in Venus' atmosphere, seen by Venus Express' Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) in 2007 (ESA) — Cloud structures in Venus’ atmosphere, seen by Venus Express’ Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) in 2007 (ESA)

By tracking the movements of distinct features in Venus’ cloud tops at an altitude of 70 km (43 miles) over a period of six years — which is 10 of Venus’ years — scientists have been able to monitor patterns in long-term global wind speeds.

What two separate studies have found is a rising trend in high-altitude wind speeds in a broad swath south of Venus’ equator, from around 300 km/h when Venus Express first entered orbit in 2006 to 400 km/h (250 mph) in 2012. That’s nearly double the wind speeds found in a category 4 hurricane here on Earth!

“This is an enormous increase in the already high wind speeds known in the atmosphere. Such a large variation has never before been observed on Venus, and we do not yet understand why this occurred,” said Igor Khatuntsev from the Space Research Institute in Moscow and lead author of a paper to be published in the journal Icarus.

Long-term studies based on tracking the motions of several hundred thousand cloud features, indicated here with arrows and ovals, reveal that the average wind speeds on Venus have increased from roughly 300 km/h to 400 km/h over the first six years of the mission. (Khatuntsev et al.)

A complementary Japanese-led study used a different tracking method to determine cloud motions, which arrived at similar results… as well as found other wind variations at lower altitudes in Venus’ southern hemisphere.

“Our analysis of cloud motions at low latitudes in the southern hemisphere showed that over the six years of study the velocity of the winds changed by up 70 km/h over a time scale of 255 Earth days – slightly longer than a year on Venus,” said Toru Kouyama from Japan’s Information Technology Research Institute. (Their results are to be published in the Journal of Geophysical Research.)

Both teams also identified daily wind speed variations on Venus, along with shifting wave patterns that suggest “upwelling motions in the morning at low latitudes and downwelling flow in the afternoon.” (via Cloud level winds from the Venus Express Monitoring Camera imaging, Khatuntsev et al.)

A day on Venus is longer than its year, as the planet takes 243 Earth days to complete a single rotation on its axis. Its atmosphere spins around it much more quickly than its surface rotates — a curious feature known as super-rotation.

“The atmospheric super-rotation of Venus is one of the great unexplained mysteries of the Solar System,” said ESA’s Venus Express Project Scientist Håkan Svedhem. “These results add more mystery to it, as Venus Express continues to surprise us with its ongoing observations of this dynamic, changing planet.”

June 18, 2013December 23, 2015 by David Dickinson

Will Comet ISON Dazzle our Skies? An Expert Weighs In

ISON as seen by Hubble earlier this spring. (Credit: NASA/ESA/Z. Levay/STScl).

Comets are the big “question marks” of observational astronomy. Some, such as Comet Hyakutake and the Great Daylight Comet of 1910 present themselves seemingly without warning and put on memorable displays. Others, such as the infamous Comet Kohoutek or Comet Elenin, fizzle and fail to perform up to expectations after a much anticipated round of media hype.

And then there’s the case of Comet C/2012 S1 ISON. Discovered on September 21^st, 2012 by Artyom Novichonok and Vitali Nevski while conducting the International Scientific Optical Network (ISON) survey, Comet ISON has captivated public interest. The media loves a good comet, or at least the promise of one.

But will Comet ISON perform up to expectations? Recently, veteran comet hunter and observer John Bortle weighed in on a Sky & Telescope post and an email interview with Universe Today on what we might expect to see this fall.

Dozens of comets are discovered every year. Most amount to nothing – a handful, like this year’s comet 2011 L4 PanSTARRS or 2012 F6 Lemmon, may become interesting binocular objects.

Part of what alerted astronomers that Comet ISON may become something special was its extreme discovery distance of 6.7 astronomical units (A.U.s) meaning it should be an intrinsically bright object, coupled with its close approach of 0.012 A.U.s (1.1 million kilometres, accounting for the solar radius) from the surface of the Sun at perihelion.

Universe Today recently caught up with Mr. Bortle, who had the following to say above tentative prospects for Comet ISON in late 2013:

“Comets coming into the near-solar neighborhood from the Oort Cloud for the very first time tend to behave rather differently from most of their other icy brethren. They often will show considerable early activity while still far from the Sun, giving a false sense of their significance. Only when they have ventured to within about 1.5-2.0 astronomical units of the Sun do they begin to reveal their true intrinsic nature in the way of brightness and development. When discovered far from the Sun, this situation has misled astronomers time and again into announcing that a grandiose display is in the offing, only to have the comet ultimately turn out to be a general disappointment. There have been exception to this, but they are rare indeed.”

Comet ISON bears similar characteristics to many of the great sungrazing comets of the past. In the last few months, word has made rounds that Comet ISON may be underperforming, stagnating around magnitude +16 (10,000 times fainter than naked eye visibility) as it crosses the expanse of the asteroid belt between Jupiter and Mars.

Bortle, however, cautioned against writing off ISON just yet in a recent message board post. “With this comet’s exceedingly small perihelion distance, the ultimate situation is less clear.” He also continues to note that the prospects for ISON are “really difficult to predict at the moment,” but estimates that Comet ISON “will not actually attain naked eye brightness until just a week or two before perihelion passage.”

Regarding naked eye visibility of Comet ISON, Mr. Bortle also told Universe Today:

“In all probability this will not occur until around early to mid-November. It will not become any sort of impressive sight before disappearing into the morning twilight only a couple of weeks thereafter.”

And that’s the big question that may make the difference between a fine binocular comet and the touted “Comet of the Century…” Will this comet survive its perihelion passage on November 28^th?

Concerning the comet’s perihelion passage, Mr. Bortle told Universe Today:

“This is currently a matter of some concern to me. Basing my answer on ISON’s apparent brightness when it was last seen before disappearing into the evening twilight recently suggests that it might be close in intrinsic brightness to the survival/non-survival level for such an extremely close encounter with the Sun. We will know much better once we can view ISON again in September.”

Comet Ikeya-Seki was another sungrazing comet that went on to become a splendid naked eye comet in 1965. The late 1880’s hosted a slew of memorable comets, including two long-tailed sungrazers, one each in 1880 and 1887.

In more recent times, Comet C/2011 W3 Lovejoy survived its December 16^th, 2011 perihelion passage 140,000 kilometres from the surface of the Sun to become the surprise hit for southern hemisphere observers.

“IF” comet ISON breaks a negative magnitude, it’ll join the ranks on the top brightest comets since 1935. If it tops -10th magnitude, it’ll best Comet Ikeya-Seki at its maximum in 1965. The magic “brighter than a Full Moon” threshold sits right about at magnitude -12.5, but Bortle cautions that this peak brightness will only persist during the hours surrounding perihelion, when the comet will be very close to the Sun and difficult to see.

Mr. Bortle also voiced a concern to Universe Today that “the initial announcements by professional astronomers concerning ISON’s potential future brightness (“Brighter than the Full Moon”, etc.) were wildly excessive, as was the idea that the comet would be obvious to the general public in the daytime sky as it rounded the Sun in late November. This claim was totally unjustified from the word go.” Mr Bortle also warns that this may be “headed us down the exact same road as the Kohoutek fisaco of 1973/74.”

We’re currently losing Comet ISON behind the Sun as it crosses through the constellation Gemini, not return to morning skies until late August. The comet will cross the orbit of Mars in early October and should also cross the +10^th magnitude threshold and become visible in binoculars and small telescopes around this date.

The track of Comet ISON through the constellations Gemini, Cancer and Leo prior to perihelion. (Credit: NASA/GSFC/Axel Mellinger).

From October on in, things should get really interesting. Mr. Bortle predicts that the comet will “develop more slowly in the autumn sky than initially thought,” and won’t become a naked eye object until around November 10^th or so. What this sort of lag might do to the internet pundits and prognosticators might be equally interesting to watch.

ISON will also track near some interesting morning objects as seen from Earth, including Mars (October 18^th), Spica (November 18^th), and Mercury & Saturn low in the dawn on November 26^th. It will also have another famous comet nearby on November 25^th (photo op!) short period Comet 2P Encke.

If Comet ISON survives perihelion, the true show could begin in early December. Comet ISON will re-emerge in the dawn skies, passing a pairing of Mercury and the very old crescent Moon on December 1^st. Comet tails are even less predictable than comet magnitudes, but if Comet ISON is to unfurl a long photogenic tail, the weeks leading up to Christmas may be when it does it.

The projected view of Comet ISON from 30 degrees north latitude 30 minutes prior to local sunrise on December 1st. The orbital path of the comet and the ecliptic are also depicted. (Created by the author in Starry Night).

Mr. Bortle predicts a 10 to 15 degree long tail for a post-perihelion ISON as it passes through the constellation Ophiuchus into morning skies. It may become a “headless wonder” similar to the fan-shaped display put on by Comet 2011 L4 PanSTARRS earlier this spring. We’ve even seen models projecting a great fan-shaped dust tail seeming to “loop” around the Sun as seen from our Earthly vantage point!

All interesting conjecture to watch unfold as Comet ISON approaches perihelion this November. Hopefully, the hysteria that follows great cometary apparitions won’t reach a fevered pitch, though we’ve already had to put some early conspiracies to bed surrounding comet ISON.

Will ISON be the “Comet of the Century?” Watch this space… we’ll have more on the play-by-play action as it approaches!

-Read John Bortle’s predictions for Comet ISON in his recent Sky & Telescope post.

June 18, 2013December 23, 2015 by Elizabeth Howell

Uranus Is Being Chased By Asteroids!

A Sharper View Of Uranus — Uranus viewed in the infrared spectrum, revealing internal heating and its ring system. Image Credit: Lawrence Sromovsky, (Univ. Wisconsin-Madison), Keck Observatory

As Uranus speeds in its orbit in the solar system, there are three large space rocks that are in lockstep with the gas giant, according to new simulations. Two of them are wobbling in unstable “horseshoe” orbits near Uranus, while the third is in a more reliable Trojan orbit that is always 60 degrees in front of the planet.

The largest of this small group is the asteroid Crantor, which is 44 miles (70 kilometers) wide. Its horseshoe orbit, and that of companion 2010 EU65, means the space rocks seesaw between being close to Uranus and further away. They should stay in that configuration for a few million years.

The last of the group is 2011 QF99, in a Trojan orbit near one of Uranus’ Lagrangian points — sort of like a celestial parking spot where an object can hang out without undue influence from the balanced gravitational forces.

An artists impression of an asteroid belt(credit: NASA)

The results illustrate the importance of space rocks that are outside of the main asteroid belt between Mars and Jupiter.

There are several kinds of these asteroids (classified by their orbits) that follow around planets in the solar system. Earth itself, for example, has at least one Trojan asteroid.

“Crantor currently moves inside Uranus’ co-orbital region on a complex horseshoe orbit. The motion of this object
is primarily driven by the influence of the Sun and Uranus, although Saturn plays a significant role in destabilizing its orbit,” the authors wrote in their new study.

“Although this object follows a temporary horseshoe orbit, more stable trajectories are possible and we present 2010 EU65 as a long-term horseshoe librator candidate in urgent need of follow-up observations.”

The results are described in Crantor, a short-lived horseshoe companion to Uranus (Astronomy & Astrophysics, March 3, 2013.)

Source: Servicio de informacíon y noticias cientifícas

June 18, 2013December 23, 2015 by Nancy Atkinson

Astrophoto: Fireworks and the Quarter Moon

Fireworks and the quarter Moon seen over the skies of Pisa, Italy on June 16, 2013. Credit and copyright: Giuseppe Petricca.

This lovely image of the Moon with fireworks exploding nearby in the sky was taken by astrophotgrapher Giuseppe Petricca over the weekend. “In Pisa, it was the Patron Saint’s Day, and I managed to catch fireworks, launched from the middle of the river Arno, exploding near the first quarter Moon!” This is an actual shot — not a mosaic — and Guiseppe said he only used Photoshop to make the Moon’s surface detail more clear and reduced the overall noise in the picture.

The event must have been awe-inspiring in person!

This image taken with a Nikon P90 Bridge Digital Camera on tripod.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

June 18, 2013December 23, 2015 by Nancy Atkinson

NASA Names First Astronaut Class for Deep Space Exploration

On Monday, NASA introduced eight new astronaut candidates – four women and four men – who will “help the agency push the boundaries of exploration and travel to new destinations in the solar system,” NASA said.

“This is the first class in three years, and the 21st overall in our nation’s nearly 55-year journey in space,” said NASA Associate Administrator Lori Garver in a blog post. “From a near-record number of applicants, more than 6,100, we selected an extremely qualified class that represents a high degree of achievement and dedication to our nation’s future.”

This is the highest percentage of female candidates ever selected for a class.

“That was not by choice or by determination,” said Janet Kavandi, a veteran astronaut and the director of Flight Crew Operations for NASA, speaking during a Google Plus Hangout where the new astronauts were introduced. “We never determine how many people of each gender we’re going to take, but these were the most qualified people of the ones that we interviewed. They earned every bit of the right to be there.”

Kavandi added that the new class is “an amazing group of people.”

You can watch a replay of the Hangout below:

The new astronauts candidates will undergo several years of training to become official astronauts. Right now NASA has 48 in the astronaut corps, which is about one-third the size it was at its peak a during the space shuttle heydays.

“With a smaller astronaut corps and fewer people in the office, now each person needs to have as diverse a background as possible” Kavandi said, “so we tried to work hard to make sure that the eight people we got had a broad spectrum of experiences, and I think you can tell that from their qualifications.”

NASA said the new astronauts will receive a wide array of technical training to prepare for missions to low-Earth orbit, an asteroid and Mars.

“These new space explorers asked to join NASA because they know we’re doing big, bold things here — developing missions to go farther into space than ever before,” said NASA Administrator Charles Bolden. “They’re excited about the science we’re doing on the International Space Station and our plan to launch from U.S. soil to there on spacecraft built by American companies. And they’re ready to help lead the first human mission to an asteroid and then on to Mars.”

The new astronaut candidates are:

Josh A. Cassada, Ph. D., 39, is originally from White Bear Lake, Minn. Cassada is a former naval aviator who holds an undergraduate degree from Albion College, and advanced degrees from the University of Rochester, N.Y. Cassada is a physicist by training and currently is serving as co-founder and Chief Technology Officer for Quantum Opus.

Victor J. Glover, 37, Lt. Commander, U.S. Navy, hails from Pomona, Calif., and Prosper, Texas. He is an F/A-18 pilot and graduate of the U.S. Air Force Test Pilot School. Glover holds degrees from California Polytechnic State University, San Luis Obispo, Calif.; Air University and Naval Postgraduate School. He currently is serving as a Navy Legislative Fellow in the U.S. Congress.

Tyler N. Hague (Nick), 37, Lt. Colonel, U.S. Air Force, calls Hoxie, Kan., home. He is a graduate of the U.S. Air Force Academy, Massachusetts Institute of Technology, and the U.S. Air Force Test Pilot School, Edwards, Calif. Hague currently is supporting the Department of Defense as Deputy Chief of the Joint Improvised Explosive Device Defeat Organization.

Christina M. Hammock, 34, calls Jacksonville, N.C. home. Hammock holds undergraduate and graduate degrees from North Carolina State University, Raleigh, N.C. She currently is serving as National Oceanic and Atmospheric Administration (NOAA) Station Chief in American Samoa.

Nicole Aunapu Mann, 35, Major, U.S. Marine Corps, originally is from Penngrove, Calif. She is a graduate of the U.S. Naval Academy, Stanford (Calif.) University and the U.S. Naval Test Pilot School, Patuxent River, Md. Mann is an F/A 18 pilot, currently serving as an Integrated Product Team Lead at the U.S. Naval Air Station, Patuxent River.

Anne C. McClain, 34, Major, U.S. Army, lists her hometown as Spokane, Wash. She is a graduate of the U.S. Military Academy at West Point, N.Y.; the University of Bath and the University of Bristol, both in the United Kingdom. McClain is an OH-58 helicopter pilot, and a recent graduate of U.S. Naval Test Pilot School at Naval Air Station, Patuxent River.

Jessica U. Meir, Ph.D., 35 is from Caribou, Maine. She is a graduate of Brown University, has an advanced degree from the International Space University, and earned her doctorate from Scripps Institution of Oceanography. Meir currently is an Assistant Professor of Anesthesia at Harvard Medical School, Massachusetts General Hospital, Boston.

Andrew R. Morgan, M.D., 37, Major, U.S. Army, considers New Castle, Pa., home. Morgan is a graduate of The U.S. Military Academy at West Point, and earned doctorate in medicine from the Uniformed Services University of the Health Sciences, Bethesda, Md. He has experience as an emergency physician and flight surgeon for the Army special operations community, and currently is completing a sports medicine fellowship.

You can read more about each of the astronauts here.

June 18, 2013December 23, 2015 by Ken Kremer

Final Construction Starts for Europe’s 2016 Methane Sniffing Mars Mission

The European/Russian ExoMars Trace Gas Orbiter (TGO) will launch in 2016 and sniff the Martian atmosphere for signs of methane which could originate for either biological or geological mechanisms. Credit: ESA

Has life ever existed on Mars? Or anywhere beyond Earth?

Answering that question is one of the most profound scientific inquiries of our time.

Europe and Russia have teamed up for a bold venture named ExoMars that’s set to blast off in search of Martian life in about two and a half years.

Determining if life ever originated on the Red Planet is the primary goal of the audacious two pronged ExoMars missions set to launch in 2016 & 2018 in a partnership between the European and Russian space agencies, ESA and Roscosmos.

In a major milestone announced today (June 17) at the Paris Air Show, ESA signed the implementing contract with Thales Alenia Space, the industrial prime contractor, to start the final construction phase for the 2016 Mars mission.

“The award of this contract provides continuity to the work of the industrial team members of Thales Alenia Space on this complex mission, and will ensure that it remains on track for launch in January 2016,” noted Alvaro Giménez, ESA’s Director of Science and Robotic Exploration.

ExoMars 2016 Mission to the Red Planet. It consists of two spacecraft - the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. Credit: ESA — ExoMars 2016 Mission to the Red Planet. It consists of two spacecraft – the Trace Gas Orbiter (TGO) and the Entry, Descent and Landing Demonstrator Module (EDM) which will land. Credit: ESA

The ambitious 2016 ExoMars mission comprises of both an orbiter and a lander- namely the methane sniffing Trace Gas Orbiter (TGO) and the piggybacked Entry, Descent and Landing Demonstrator Module (EDM).

ExoMars 2016 will be Europe’s first spacecraft dispatched to the Red Planet since the 2003 blast off of the phenomenally successful Mars Express mission – which just celebrated its 10th anniversary since launch.

Methane (CH4) gas is the simplest organic molecule and very low levels have reportedly been detected in the thin Martian atmosphere. But the data are not certain and its origin is not clear cut.

Methane could be a marker either for active living organisms today or it could originate from non life geologic processes. On Earth more than 90% of the methane originates from biological sources.

The ExoMars 2016 orbiter will investigate the source and precisely measure the quantity of the methane.

The 2016 lander will carry an international suite of science instruments and test European landing technologies for the 2nd ExoMars mission slated for 2018.

The 2016 ExoMars Trace Gas Orbiter will carry and deploy the Entry, Descent and Landing Demonstrator Module to the surface of Mars. Credit: ESA-AOES Medialab

The 2018 ExoMars mission will deliver an advanced rover to the Red Planet’s surface. It is equipped with the first ever deep driller that can collect samples to depths of 2 meters where the environment is shielded from the harsh conditions on the surface – namely the constant bombardment of cosmic radiation and the presence of strong oxidants like perchlorates that can destroy organic molecules.

ExoMars was originally a joint NASA/ESA project until hefty cuts to NASA’s budget by Washington DC politicians forced NASA to terminate the agencies involvement after several years of detailed work.

Elements of the ExoMars program 2016-2018. Credit: ESA

Thereafter Russia agreed to take NASA’s place and provide the much needed funding and rockets for the pair of planetary launches scheduled for January 2016 and May 2018.

NASA does not have the funds to launch another Mars rover until 2020 at the earliest – and continuing budget cuts threaten even the 2020 launch date.

NASA will still have a small role in the ExoMars project by funding several science instruments.

The ExoMars missions along with NASA’s ongoing Curiosity and Opportunity Mars rovers will pave the way for Mars Sample Return missions in the 2020’s and eventual Humans voyages to the Red Planet in the 2030’s.

And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013

Ken Kremer

…………….
Learn more about Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations

June 23: “Send your Name to Mars on MAVEN” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

June 17, 2013December 23, 2015 by Nancy Atkinson

Insane Timelapse of a Rotating Supercell Looks Like an Alien Spaceship

An impressive, gorgeous, powereful supercell northwest of Booker, Texas from June 3rd, 2013. Credit and copyright: Mike Olbinski/Olbinski Photography.

Photographer and storm chaser Mike Olbinski has captured some incredible storm footage over the years (such as this apocalyptic haboob in Arizona in 2011.) But his latest timelapse was something he’s been chasing down for over four years: a rotating supercell. Mike lives in Arizona, where that type of storm doesn’t happen. But he regularly visits the US Central Plains and said on his website that he’s been hoping to capture footage of “clouds that rotate and look like alien spacecraft hanging over the Earth.”

To quote Mike again, “Boy, did we find it.”

On June 3, 2013 he and his team were following storms near Booker, Texas. “We chased this storm from the wrong side (north) and it took us going through hail and torrential rains to burst through on the south side. And when we did…this monster cloud was hanging over Texas and rotating like something out of Close Encounters.”

Watch it below:

It never turned into a tornado, thankfully.

The timelapse was shot on a Canon 5D Mark II with a Rokinon 14mm 2.8 lens.

Mike says:

It’s broken up into four parts. The first section ends because it started pouring on us. We should have been further south when we started filming but you never know how long these things will last, so I started the timelapse as soon as I could.

One thing to note early on in the first part is the way the rain is coming down on the right and actually being sucked back into the rotation. Amazing.

This video has gone viral, and unfortunately some sites aren’t crediting Mike as the photographer. But just to be clear, this is a Mike Olbinski original!

Read more on his website, and see more of his videos on his Vimeo page.

June 17, 2013December 23, 2015 by Nancy Atkinson

Final Command Shuts Down Herschel Telescope

Screens in ESOC's Main Control Room on the day the last command was sent to the Herschel Space Telescope, shutting the observatory off. Credit: ESA.

We knew it was coming, but it is still sad to see the end of a mission. Controllers for the Herschel space telescope sent final commands today to put the observatory into a heliocentric parking orbit. Commands were sent at 12:25 GMT on June 17, 2013, marking the official end of operations for Herschel. But expect more news from this spacecraft’s observations, as there is still a treasure trove of data that that will keep astronomers busy for many years to come. Additionally, maneuvers done by the spacecraft allowed engineers to test out control techniques that can’t normally be tested in-flight during a mission.

You can watch a video of Herschel’s final “live” moments below:

Herschel’s science mission had already ended in April when the liquid helium that cooled the observatory’s instruments ran out.

Herschel will now be parked indefinitely in a heliocentric orbit, as a way of “disposing” of the spacecraft. It should be stable for hundreds of years, but perhaps scientists will figure out another use for it in the future. One original idea for disposing of the spacecraft was to have it impact the Moon, a la the LCROSS mission that slammed into the Moon in 2009, and it would kick up volatiles at one of the lunar poles for observation by another spacecraft, such as the Lunar Reconnaissance Orbiter. But that idea has been nixed in favor of the parking orbit.

Some of the maneuvers that were tested before the spacecraft was put into its final orbit were some in-orbit validations and analysis of hardware and software.

ESA's Herschel telescope used liquid helium to keep cool while it observed heat from the early Universe. Credit: ESA — ESA’s Herschel telescope used liquid helium to keep cool while it observed heat from the early Universe. Credit: ESA

“Normally, our top goal is to maximise scientific return, and we never do anything that might interrupt observations or put the satellite at risk,” says Micha Schmidt, Herschel’s Spacecraft Operations Manager at the European Space Operations Center. “But the end of science meant we had a sophisticated spacecraft at our disposal on which we could conduct technical testing and validate techniques, software and the functionality of systems that are going to be reused on future spacecraft. This was a major bonus for us.”

The test requests came from other missions. For example, the ExoMars team requested doing some validations using Herschel’s Visual Monitoring Camera since ExoMars will have a similar camera, and the Euclid spacecraft team asked for some reaction wheel tests.
On May 13-14, engineers commanded Herschel to fire its thrusters for a record 7-hours and 45-minutes. This ensured the satellite was boosted away from its operational orbit around the L2 Sun–Earth Lagrange Point and into a heliocentric orbit, further out and slower than Earth’s orbit. This depleted most of the fuel, and the final thruster command today used up all of the remaining fuel. Today’s final command was the last step in a complex series of flight control activities and thruster maneuvers designed to take Herschel into a safe disposal orbit around the Sun; additionally all its systems were turned off.

“Herschel has not only been an immensely successful scientific mission, it has also served as a valuable flight operations test platform in its final weeks of flight. This will help us increase the robustness and flexibility of future missions operations,” said Paolo Ferri, ESA’s Head of Mission Operations. “Europe really received excellent value from this magnificent satellite.”

Source: ESA

June 17, 2013October 18, 2016 by Fraser Cain

What is the Hottest Planet in the Solar System?

Earth is the third planet from the Sun, and the climate here is just right for life. Here in our Solar System, there are planets both hotter and colder than Earth.

So… which one is the hottest?

You might think it’s Mercury, the planet closest to the Sun. Mercury orbits at a distance of only 58 million kilometers, travelling in a blast-furnace of scorching radiation. Its temperature can skyrocket to 700 Kelvin, or 426 degrees Celsius on the sunward side. In the shadows, temperatures plunge down to 80 Kelvin, which is -173 degrees Celsius

Mercury sure is hot, but Venus is hotter.

Venus imaged by Magellan Image Credit: NASA/JPL

Venus is much further from the Sun, orbiting at a distance of more than 108 million kilometers. Average temperature there is a hellish 735 Kelvin, or 462 degrees Celsius – hot enough to melt lead.

Venus remains that same temperature no matter where you go on the planet. At the North Pole? 735 Kelvin. At night? 735 Kelvin. Daytime at the equator? You get the point.

So, why is Venus so much hotter than Mercury, even though it’s further away from the Sun? It’s all about the atmosphere.

Mercury is an airless world, not unlike the Moon. Venus, has a very thick atmosphere of CO2, which adds incredible pressure, and traps in the heat.

Consider our own planet. When you stand at sea level on Earth, you’re experiencing one atmosphere of pressure. But if you could stand on the surface of Venus – and trust me, you don’t want to – you’d experience ninety-two times as much atmospheric pressure. This is the same kind of pressure as being a kilometer underneath the surface of the ocean.

Venus also shows us what happens when carbon dioxide levels just keep on rising. Radiation from the Sun is absorbed by the planet, and the infrared heat emitted is trapped by the carbon dioxide, which creates a runaway greenhouse effect.

You might think a planet this hot with such extreme temperature and pressure, would be impossible to explore.

And if you did, you’d be wrong.

The Soviets sent a series of spacecraft called Venera, which parachuted down through the thick atmosphere and returned images from the surface of Venus. Although the first few missions were failures, this taught the Soviets just how hellish the Venusian environment really is.

Venera 13 made it down to the surface in nineteen-eighty-one and survived for one-hundred-and-twenty-seven minutes, sending back the first color pictures of Venus’ surface.

The hottest planet in our solar system is Venus,

When it comes to temperature, distance from the Sun matters, but it takes a backseat to wrapping a planet in a atmospheric blanket of carbon dioxide.

We release this explainer videos every Monday and Thursday from the Universe Today YouTube Channel. Click here to Subscribe to the channel.

June 17, 2013December 23, 2015 by Elizabeth Howell

Black Hole Bonanza! Dozens (Potentially) Found In Andromeda As Another Study Probes X-Rays

A new analysis of data from the Chandra space telescope revealed 26 black hole candidates in the Andromeda Galaxy. This is the largest collection of possible black holes found in another galaxy besides that of the Milky Way, Earth's home galaxy. Credit: X-ray (NASA/CXC/SAO/R.Barnard, Z.Lee et al.), Optical (NOAO/AURA/NSF/REU Prog./B.Schoening, V.Harvey; Descubre Fndn./CAHA/OAUV/DSA/V.Peris)

More than two DOZEN potential black holes have been found in the nearest galaxy to our own. As if that find wasn’t enough, another research group is teaching us why extremely high-energy X-rays are present in black holes.

The Andromeda Galaxy (M31) is home to 26 newly found black hole candidates that were produced from the collapse of stars that are five to 10 times as massive as the sun.

Using 13 years of observations from NASA’s Chandra X-Ray Observatory, a research team pinpointed the locations. They also corroborated the information with X-ray spectra (distribution of X-rays with energy) from the European Space Agency’s XMM-Newton X-ray observatory.

“When it comes to finding black holes in the central region of a galaxy, it is indeed the case where bigger is better,” stated co-author Stephen Murray, an astronomer at Johns Hopkins University and the Harvard-Smithsonian Center for Astrophysics.

A close-up of the candidate black holes in Andromeda, as seen by the Chandra X-Ray Observatory. Credit: X-ray (NASA/CXC/SAO/R.Barnard, Z.Lee et al.), Optical (NOAO/AURA/NSF/REU Prog./B.Schoening, V.Harvey; Descubre Fndn./CAHA/OAUV/DSA/V.Peris

“In the case of Andromeda, we have a bigger bulge and a bigger supermassive black hole than in the Milky Way, so we expect more smaller black holes are made there as well,” Murray added.

The total number of candidates in M31 now stands at 35, since the researchers previously identified nine black holes in the area. All told, it’s the largest number of black hole candidates identified outside of the Milky Way.

Meanwhile, a study led by the NASA Goddard Space Flight Center examined the high-radiation environment inside a black hole — by simulation, of course. The researchers performed a supercomputer modelling of gas moving into a black hole, and found that their work helps explain some mysterious X-ray observations of recent decades.

Researchers distinguish between “soft” and “hard” X-rays, or those X-rays that have low and high energy. Both types have been observed around black holes, but the hard ones puzzled astronomers a bit.

Here’s what happens inside a black hole, as best as we can figure:

– Gas falls towards the singularity, orbits the black hole, and gradually becomes a flattened disk;

– As gas piles up in the center of the disk, it compresses and heats up;

– At a temperature of about 20 million degrees Fahrenheit (12 million degrees Celsius), the gas emits “soft” X-rays.

So where did the hard X-rays — that with energy tens or even hundreds of times greater than soft X-rays — come from? The new study showed that magnetic fields are amplified in this environment that then “exerts additional influence” on the gas, NASA stated.

Artist's conception of the Chandra X-Ray Observatory. Credit: NASA — Artist’s conception of the Chandra X-Ray Observatory. Credit: NASA

“The result is a turbulent froth orbiting the black hole at speeds approaching the speed of light. The calculations simultaneously tracked the fluid, electrical and magnetic properties of the gas while also taking into account Einstein’s theory of relativity,” NASA stated.

One key limitation of the study was it modelled a non-rotating black hole. Future work aims to model one that is rotating, NASA added.

You can check out more information about these two studies below:

– Andromeda black holes: Chandra identification of 26 new black hole candidates in the central region of M31. (Also available in the June 20 edition of The Astrophysical Journal.)

– X-ray modelling of black holes: X-ray Spectra from MHD Simulations of Accreting Black Holes. (Also available in the June 1 edition of The Astrophysical Journal.)

Sources: Chandra X-Ray Observatory and NASA