Elizabeth Howell, Author at Universe Today

October 16, 2013December 23, 2015 by Elizabeth Howell

Was This Ridge Habitable? Mars Curiosity Eyes Nearby Mountain

Curiosity is only eight miles (five kilometers) from a hematite-rich ridge at the bottom of Mount Sharp (Aeolis Mons). Credit: NASA/JPL-Caltech/MSSS

So Curiosity has been on Mars for an Earth year and is now, slowly, making its way over to that ginormous mountain — Mount Sharp, or Aeolis Mons — in the distance. The trek is expected to take at least until mid-2014, if not longer, because the rover will make pit stops at interesting science sites along the way. But far-thinking scientists are already thinking about what areas they would like to examine when it gets there.

One of those is an area that appears to have formed in water. There’s a low ridge on the bottom of the mountain that likely includes hematite, a mineral that other Mars rovers have found. (Remember the “blueberries” spotted a few years ago?) Hematite is an iron mineral that comes to be “in association with water”, a new study reports, and could point the way to the habitable conditions Curiosity is seeking.

The rub is scientists can’t say for sure how the hematite formed until the rover is practically right next to the ridge. There are plenty of pictures from orbit, but not high-resolution enough for the team to make definitive answers.

Colors map percentages of hematite in the surface materials in Meridiani Planum on Mars from 5 percent (aqua) to 25 percent (red). Opportunity landed within the black oval. MER scientists say the rocks there had once been drenched in water. Credit: NASA

“Two alternatives are likely: chemical precipitation within the rocks by underground water that became exposed to an oxidizing environment — or weathering by neutral to slightly acidic water,” wrote Arizona State University’s Red Planet Report. Either way, it shows the ridge likely hosted iron oxidation. Earth’s experience with this type of oxidation shows that it happens “almost exclusively” with microorganisms, but that’s not a guarantee on Mars.

Mars Reconnaissance Orbiter images show that the ridge is about 660 feet (200 meters) wide and four miles (6.5 kilometers) long, with strata or layers in the ridge appearing to be similar to those of layers in Mount Sharp.

While Curiosity is not designed to seek life, it can ferret out details of the environment. Just a few weeks ago, for example, it uncovered pebbles that likely formed in the presence of water. Other Mars missions have also found evidence of that liquid, with perhaps some of it once arising from the subsurface. Where the water came from, and why the environment of Mars changed so much in the last few billion years, are ongoing scientific questions.

Check out more details on the study in Geology.

Source: Red Planet Report

October 16, 2013December 23, 2015 by Elizabeth Howell

Wet Asteroid’s Remains Found In Old Star That Could Have Hosted Habitable Planets

Artist's impression of a rocky and water-rich asteroid being torn apart by the strong gravity of the white dwarf star GD 61. Credit: Mark A. Garlick, space-art.co.uk, University of Warwick and University of Cambridge

Remains of a water-filled asteroid are circling a dying white dwarf star, right now, about 150 light-years from us. The new find is the first demonstration of water and a rocky surface in a spot beyond the solar system, researchers say.

The discovery is exciting to the astronomical team because, according to them, it’s likely that water on Earth came from asteroids, comets and other small bodies in the solar system. Finding a watery rocky body demonstrates that this theory has legs, they said. (There are, however, multiple explanations for water on Earth.)

“The finding of water in a large asteroid means the building blocks of habitable planets existed – and maybe still exist – in the GD 61 system, and likely also around substantial number of similar parent stars,” stated lead author Jay Farihi, from Cambridge’s Institute of Astronomy.

Earth’s oxygen and water as detected by Venus Express (ESA)

“These water-rich building blocks, and the terrestrial planets they build, may in fact be common – a system cannot create things as big as asteroids and avoid building planets, and GD 61 had the ingredients to deliver lots of water to their surfaces. Our results demonstrate that there was definitely potential for habitable planets in this exoplanetary system.”

More intriguing, however, is researchers found this evidence in a star system that is near the end of its life. So the team is framing this as a “look into our future”, when the Sun evolves into a white dwarf .

The water likely came from a “minor planet” that was at least 56 miles (90 kilometers) in diameter. Its debris was pulled into the atmosphere of the star, which was then examined by spectroscopy. This study revealed the ingredients of rocks inside the star, including magnesium, silicon and iron. Researchers then compared these elements to how abundant oxygen was, and found that there was in fact more oxygen than expected.

“This oxygen excess can be carried by either water or carbon, and in this star there is virtually no carbon – indicating there must have been substantial water,” stated co-author Boris Gänsicke, from the University of Warwick.

“This also rules out comets, which are rich in both water and carbon compounds, so we knew we were looking at a rocky asteroid with substantial water content – perhaps in the form of subsurface ice – like the asteroids we know in our solar system such as Ceres.”

The measurements were obtained in ultraviolet with the Hubble Space Telescope’s cosmic origins spectrograph. What’s more, the researchers suspect there are giant exoplanets in the area because it would take a huge push to move this object from the asteroid belt — a push that most likely came from big planet.

“This supports the idea that the star originally had a full complement of terrestrial planets, and probably gas giant planets, orbiting it – a complex system similar to our own,” Farihi added.

The discovery was recently published in Science.

Source: University of Cambridge

October 16, 2013December 23, 2015 by Elizabeth Howell

Possible Huge Meteorite Fragment Recovered From Russian Fireball

Frame grab from a video of the Feb. 15, 2013 Russian fireball by Aleksandr Ivanov

A half-ton meteorite — presumably from the Russian fireball that broke up over Chelyabinsk in February — was dragged up from Lake Chebarkul in the Urals, Russian media reports said. Scientists estimate the chunk is about 1,260 pounds (570 kilograms), but couldn’t get a precise measurement in the field because the bulky bolide broke the scale, according to media reports.

“The preliminary examination… shows that this is really a fraction of the Chelyabinsk meteorite,” said Sergey Zamozdra, associate professor of Chelyabinsk State University, in reports from Interfax and RT.

A polished slice of one of Russian meteorite samples. You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5. — A polished slice of one of Russian meteorite samples (different samples than what was reportedly recovered on Oct. 16). You can see round grains called chondrules and shock veins lined with melted rock. The meteorite is probably non-uniform. The preliminary analysis showed that the meteorite belongs to chemical type L or LL, petrologic type 5.

“It’s got thick burn-off, the rust is clearly seen and it’s got a big number of indents. This chunk is most probably one of the top ten biggest meteorite fragments ever found.”

The big rock was first spotted in September, but it’s taken several attempts to bring it to the surface. If scientists can confirm this came from the fireball, this would be the biggest piece recovered yet. The chunk is reportedly in a natural history museum, where a portion will be X-rayed to determine its origins.

More than 1,000 people were injured and millions of dollars in damage occurred when the meteor broke up in the atmosphere Feb. 15, shattering glass and causing booms.

Since then, there have been numerous papers concerning the meteor’s origins (from the Apollo class of asteroids — you can read this article if you’re unclear on the difference between an asteroid and a meteorite) and tracking the spread of dust through the atmosphere, among other items.

October 15, 2013April 26, 2016 by Elizabeth Howell

Masked Starbirth Mapped In New Milky Way Survey

Artist's conception of a star being born, within a protective shroud of gas and dust. New research shows that magnetic winds aid the growth of both protostars and SMBHs. Credit: NASA

Stars are born in private. Hidden in dust and gas clouds, these bright beacons in the universe slowly coalesce. All that debris makes it hard to spot the stars, but mapping out the pockets of starbirth is a good start to understanding what is going on inside.

A new survey tracked down 6,000 of these areas in our galaxy (the Milky Way), with the aim of understanding more about what happens when stars are just starting to come together. Most surveys, the team says, focus more on the “protostar” stage, when these objects are starting to look recognizably like stars.

“Starless clumps have only been detected in small numbers to date,” stated Yancy Shirley, an astronomer with the University of Arizona’s Steward Observatory who led the research. “Now, for the first time, we have seen this earliest phase of star formation, before a cluster actually forms, in large numbers in an unbiased way.”

Artist's conception of the Milky Way galaxy. Credit: Nick Risinger — Artist’s conception of the Milky Way galaxy. Credit: Nick Risinger

These areas are difficult to peer through in visible light, but radio works just fine. The astronomers used the Sub-Millimeter Telescope at the Arizona Radio Observatory to conduct the survey, which looks at “all parts of the galactic plane visible from the northern hemisphere”, the team says.

It’s the first survey to show the environments where different stages of starbirth take place. While the team did not immediately disclose their plans for a follow-up in a press release, they state that one aim of mapping these areas is to “better understand how the properties of these regions change as star formation progresses.”

Read all about the survey in The Astrophysical Journal, or the preprint version on Arxiv.

Source: University of Arizona

October 15, 2013December 23, 2015 by Elizabeth Howell

To The Moon! Crowdfunded Solar Sail Shoots For Lunar Launch

This Lunarsail concept from the Aerospace Research and Engineering Systems Institute successfully met its crowdfunding goal and is applying to get on a NASA rocket in the next few years. Source: Kickstarter (screenshot)

It’s a tiny satellite with ambitious goals: to zip all the way from the Earth to the Moon using a solar sail. A typical “cubesat” satellite sticks around Earth’s orbit to do a science, but the team behind Lunarsail convinced dozens of crowfunding donors that their concept can go even further.

The team asked for $11,000 on Kickstarter and actually received more than $15,000. The next step is to submit a formal proposal to NASA to hitch a ride on a rocket and get into space. (An announcement of opportunity was on NASA’s website in mid-August, but the link is currently unavailable as the agency’s site is shut down amid the government furlough. The posted deadline was Nov. 26).

“Common sense seems to suggest that cubesats don’t have the power or the huge rocket they would need to reach the Moon. Common sense can be deceptive, though,” the team wrote on their crowdfunding campaign page.

NCube-2 cubesat, a typical configuration for this kind of satellite (although the outer skin is missing.) Credit: ARES Institute

“It doesn’t take a more powerful spacecraft … the satellite doesn’t care what orbit it’s in — it just does its thing. It also doesn’t require a more powerful rocket. All we need is a rocket powerful enough to put the spacecraft into an appropriate orbit around the Earth, and then we can take over and get ourselves to the Moon.”

The Aerospace Research & Engineering Systems (ARES) Institute, which is the entity behind Lunarsail, further plans to involve students in the campaign. It’s asking around to see if there are any interested parties who could “bring mission-related science activities to thousands of students, particularly those in minority and at-risk communities.” If this goes forward, students could participate through experiments, observations and also with mobile apps.

While the team acknowledges it takes time to get a concept on a rocket and into space, they have a goal of having everything “flight-ready” by December 2016. Follow updates on the project at its web page.

October 15, 2013December 23, 2015 by Elizabeth Howell

Future Supernova Is Surrounded By Hydrogen Clouds

A "super star cluster", Westerlund 1, which is about 16,000 light-years from Earth. It can be found in the southern constellation of Ara. The picture was taken from the European Southern Observatory's VLT Survey Telescope. Credit: ESO/VPHAS+ Survey/N. Wright

The faint green glow you see in that picture is not an early harbringer of Hallowe’en spooks. It’s hydrogen gas clouds found recently nearby W26, a future supernova in the star cluster Westerlund 1.

The European Southern Observatory’s VLT Survey Telescope in Chile spotted the hydrogen in the cluster, which has hundreds of huge stars that are only believed to be a few million years old. (Our solar system, by comparison, is about 4.5 billion years old.)

“Such glowing clouds around massive stars are very rare, and are even rarer around a red supergiant— this is the first ionised nebula discovered around such a star,” the European Southern Observatory stated.

“W26 itself would be too cool to make the gas glow; the astronomers speculate that the source of the ionizing radiation may be either hot blue stars elsewhere in the cluster, or possibly a fainter, but much hotter, companion star to W26.”

Funny enough, the nebula that surrounds the red supergiant is similar to the one surrounding SN1987A, a star that exploded as a fairly bright supernova in 1987. “Studying objects like this new nebula around W26 will help astronomers to understand the mass loss processes around these massive stars, which eventually lead to their explosive demise,” ESO added.

Source: European Southern Observatory

October 11, 2013December 23, 2015 by Elizabeth Howell

Chris Hadfield Regretted Not Being Able To Make One Last Spacewalk

Chris Hadfield during an EVA in 2001. Credit: NASA

Chris Hadfield loved spacewalking. That was clear in a past interview he did for Universe Today:

It is like coming around a corner and seeing the most magnificent sunset of your life, from one horizon to the other where it looks like the whole sky is on fire and there are all those colors, and the sun’s rays look like some great painting up over your head. You just want to open your eyes wide and try to look around at the image, and just try and soak it up. It’s like that all the time. Or maybe the most beautiful music just filling your soul. Or seeing an absolutely gorgeous person where you can’t just help but stare. It’s like that all the time.

Late in Hadfield’s final mission to space this May, when the Canadian Space Agency (CSA) astronaut was commanding the International Space Station Expedition 35 crew, an ammonia leak happened and NASA had to scramble a plan for a spacewalk, or extravehicular activity (EVA), to fix it. (The fix succeeded.) When Hadfield was apprised of the plan, he says in an excerpt from his forthcoming book, he was disappointed:

I wasn’t going out. I had a moment where I allowed myself to experience the full force of my disappointment. This would have been the heroic climax of my stint as commander: helping to save the ISS by doing an emergency spacewalk. I’d never have another chance to do an EVA—I’d already informed the CSA that I planned to retire shortly after returning to Earth.

But Chris [Cassidy] and Tom [Marshburn] had both done three previous EVAs, two of them together, on the same part of the station where ammonia was now leaking. They were the obvious people for the job. All this went through my head and heart for a minute or two, then I made a resolution: I was not going to hint that I’d had this pang of envy, or say, even once, that I wished I was doing the EVA. The right call had been made, and I needed to accept it and move on so that we could all focus on the main thing—the only thing, really: working the problem.

An Astronaut’s Guide to Live On Earth isn’t out until Nov. 3, but Maclean’s magazine has a lengthy excerpt that not only talks about the spacewalk, but some behind-the-scenes discussion on Hadfield’s awe-inspiring version of David Bowie’s “Space Oddity” recorded on the International Space Station.

October 11, 2013December 23, 2015 by Elizabeth Howell

Stunning Dunes, Crevices And Horizons From Mars Spacecraft

Dunes in Noachis Terra on Mars. Credit: NASA/JPL/University of Arizona

Who doesn’t love Mars? Amid the bad news of a U.S. government shutdown now stretching towards Day 12, there are still several spacecraft from NASA and the European Space Agency taking pictures of that red dot in the sky. Here are some recent stunners from the Red Planet.

Above is an infrared view of Noachis Terra as seen through the eyes of the Mars Reconnaissance Orbiter. The High Resolution Imaging Science Experiment (HiRISE) camera website (from the University of Arizona) released the picture on its website Oct. 2, with this description (in part):

“When there are perfect conditions for producing sand dunes — steady wind in one direction and just enough sand — barchan sand dunes form. The word ‘barchan’ is a Russian term because this type of dune was first described in the desert regions of Turkistan.”

MRO is run under a contract from NASA and is still operating, although its Twitter feed warns funds are running low.

Mosaic of Hebes Chasma by ESA's Mars Express. Credit: ESA/DLR/FU Berlin (G. Neukum) — Mosaic of Hebes Chasma by ESA’s Mars Express. Credit: ESA/DLR/FU Berlin (G. Neukum)

Mars Express is a European Space Agency spacecraft and is thus not affected by the shutdown. This mosaic of eight images released Oct. 8 (above) shows Hebes Chasma, which is about 186 miles (300 kilometers) north of Valles Marineris. The trench is about five miles (eight kilometers) deep at its utmost, and hundreds of miles long. “A flat-topped mesa is located in the center of Hebes Chasma, which was likely shaped by the action of wind and water,” ESA wrote.

Meanwhile, the Curiosity and Opportunity rovers are still trundling away on Mars. NASA’s Jet Propulsion Laboratory is a contract operation and is still running its missions for the time being. These pictures were downloaded from the raw image sites for the rovers (here and here) as all press updates are suspended amid the shutdown.

Raw Mars Curiosity image on Oct. 3 of Mount Sharp (Aeolis Mons) using its Mars Hand Lens Imager (MAHLI). Credit: NASA/JPL-Caltech/MSSS

Raw image of Opportunity's view of the Martian horizon on Sol 3450 earlier in October. Credit: NASA/JPL-Caltech — Raw image of Opportunity’s view of the Martian horizon on Sol 3450 earlier in October. Credit: NASA/JPL-Caltech

October 10, 2013December 23, 2015 by Elizabeth Howell

A Crash Put Pluto’s Moons Into Odd Orbits: Study

Pluto's solar system in a 2012 artist's conception. P4 and P5 are now called Kerberos and Styx, respectively. Credit: NASA/John Hopkins University Applied Physics Laboratory

A smash-up that created Pluto’s largest moon, Charon, likely sprayed debris four billion years ago that formed the genesis of the other moons scientists are spotting today, a new study concludes.

The find could explain why the satellites Styx, Nix, Kereberos and Hydra have orbital periods that are, respectively, just about exactly 3, 4, 5 and 6 times longer than Charon’s, scientists said.

“Any initially surviving satellites would likely be destroyed in collisions, but these shattered moons wouldn’t be lost; rather, their remains would stay in the Pluto/Charon system and become the starting point for building new satellites,” stated the Southwest Research Institute (SWRI), which led the study.

Artist's impression of New Horizons' encounter with Pluto and Charon. Credit: NASA/Thierry Lombry — Artist’s impression of New Horizons’ encounter with Pluto and Charon. Credit: NASA/Thierry Lombry

“In modeling the destruction of the satellites, the SWRI study found that there may be a method for moving them, or their building blocks, outward, due to the competing effects of Charon’s gravitational kicks and collisions among the debris of the disrupted satellites.”

Given Charon’s large size relative to Pluto (it’s a tenth of the dwarf planet’s size, compared to the Earth-Moon 81: 1 ratio), its large mass could easily perturb these smaller moons if they got close. Also, collisions between the debris could alter the orbits “to keep things away from Charon”, the scientists said.

Hopefully we will learn more when the NASA New Horizons spacecraft arrives at Pluto in 2015.

The findings were presented yesterday (Oct. 9) at the American Astronomical Association’s division of planetary sciences meeting in Denver; information on whether the results are peer-reviewed was not immediately available.

Source: Southwest Research Institute

October 10, 2013December 23, 2015 by Elizabeth Howell

Tranquil Galaxy With Petals Shows Clues To A Violent Past

PGC 6240, a petal-like galaxy that probably was altered by a galactic merger. Credit: ESA/Hubble & NASA with acknowledgement to Judy Schmidt

Across the universe, some 350 million light-years away, lies a galaxy that looks like it has white rose petals. Don’t let the tranquil appearance of PGC 6240 fool you as to its past, however. This galaxy in Hydrus (The Water Snake) likely was dramatically altered by a galactic merger.

There’s a bunch of evidence pointing to this. There are “star shells” of globular clusters around the galaxy, but they’re distributed unevenly — some are close in, some are way out in the distant suburbs. Also, “several wisps of material have been thrown so far that they appear to be almost detached from the galaxy altogether,” stated the Hubble European Space Agency Information Centre.

“The most likely explanation for both the galaxy’s stacked shell structure and the unexpectedly young star clusters is that PGC 6240 merged with another galaxy at some point in the recent past,” the agency added.

“Such a merger would send ripples through the galaxy and disrupt its structure, forming the concentric shells of material seen here. It would also ignite a strong burst of star formation in the galaxy, which would then trigger similar activity in nearby space — leading to the creation of new, younger globular clusters around PGC 6240.”

Source: The Hubble European Space Agency Information Centre