Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.
Astronomers are gazing closely at supernova 2014J (inset) to see what sort of triggers caused the star explosion. Credit: NASA/SAO/CXC/R. Margutti et al
X marks the spot: after probing the area where a star used to be, in X-rays, astronomers have been able to rule out one cause for the supernova explosion.
Because the Chandra X-Ray Observatory did not detect anything unusual in X-rays, astronomers say this means that a white dwarf was not responsible for pulling off material from a massive star that exploded (from Earth’s vantage point) on Jan. 21, 2014, triggering excitement from professional and amateur astronomers alike.
“While it may sound a bit odd, we actually learned a great deal about this supernova by detecting absolutely nothing,” stated study leader Raffaella Margutti of the Harvard-Smithsonian Center for Astrophysics (CfA) in Massachusetts. “Now we can essentially rule out that the explosion was caused by a white dwarf continuously pulling material from a companion star.”
So what caused it? Possibly two white dwarfs merged instead. Follow-up observations will take place in Messier 88 and the source of the explosion, which was about 12 million light-years from Earth. While that’s a long time by human standards, astronomers point out that is close on the cosmic distance scale.
The shadow of the Opportunity rover lies on the Martian surface in this picture taken on Sol 3752, on Aug. 13. The rover is on the west rim of Endeavour Crater, near the Martian equator. Its landing site was Meridani Planum. Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.
Many of us in the northern hemisphere are on summer vacation right now, and others are dreaming of it. While taking off somewhere exotic requires time and money, looking at pictures around the solar system provides cheaper thrills — in stranger places!
Several spacecraft roaming our planetary neighborhood regularly send back raw images of what they’re seeing. Here are some views from them taken in the past week.
Mars: After setting an off-word driving record, the Opportunity rover is still trundling on Mars after more than 10 years of operations. One of its latest raw images, above, shows its shadow and tracks on the surface of the Red Planet. Its heading to a destination called “Marathon Valley”, which is a likely spot for clay materials, and recently observed a transit of the moon Phobos. The rover’s computer had a brief reset, but is in good health besides that.
Tracks of the Curiosity rover crisscross Mars in this picture taken on Sol 719 (Aug. 14, 2014). Credit: NASA/JPL-Caltech
Mars: The Curiosity rover — which recently celebrated its two-year Earth birthday on Mars — has been on the move itself. Scientists are carefully moving the rover to its next science destination, about 1/3 of a mile (500 meters) away. The challenge is the extremely rocky terrain is damaging the rover’s wheels, but NASA said a recent drive through a rocky stretch produced less wear than feared.
A lava surface in southern Elysium Planitia taken by the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE). Credit: NASA/JPL/University of Arizona
Mars: These strange features spotted by the Mars Reconnaissance Orbiter are puzzling scientists. Usually the cones you see are indicative of lava features, but these are smaller than usual. “What’s really odd here is that the cones are associated with lighter areas with polygonal patterns,” stated the University of Arizona on its blog for the High Resolution Imaging Science Experiment (HiRISE). “Such polygons are commonly visible on the denser portions of lava flows, while the rougher areas have more broken-up low-density crust.”
A raw image of the Sun taken by the Solar and Heliospheric Observatory (SOHO) on Aug. 15, 2014. Credit: ESA/NASA/SOHO
Sun: The Solar and Heliospheric Observatory (SOHO) is one of a few sentinels keeping watch over the Sun for sunspots and other signs of solar activity. This allows scientists to make better predictions about when solar storms sweep over our planet, which is important for protecting satellites and infrastructure from the worst of these storms.
A raw image of Saturn taken by the Cassini spacecraft. Credit: NASA/JPL/Space Science Institute
Saturn: The Cassini spacecraft has been busily gazing at Saturn and its moons in the past week, including looking at temperatures in the atmosphere (specifically, in the upper troposphere and tropopause) in the gas giant. Just visible in this image is a huge hexagonal storm that scientists previously said acts somewhat like the Earth’s ozone hole.
A raw view of Titan taken by the Cassini spacecraft Aug. 13, 2014. Credit: NASA/JPL/Space Science Institute
Titan: Saturn’s largest moon — which contains organic compounds that could be precursors to life’s chemistry — is undergoing some changes as summer approaches. A few days ago, scientists noted that clouds are starting to form in Titan’s northern hemisphere. While they’re not sure yet if it will herald summer, scientists added that the lack of clouds before that defied models.
A close-up view of Comet 67P/Churyumov–Gerasimenko taken by the Rosetta spacecraft on Aug. 7, 2014. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Comet 67P/Churyumov–Gerasimenko: The Rosetta spacecraft just arrived at this comet on Aug. 6, and has been sending back a few images of this small body that is speeding towards the Sun. You may recognize this particular image as part of the basis for a 3-D image that was released yesterday. Meanwhile, team members are examining dust production of the comet, which has already started as it heads to its closest Sun approach (between Earth and Mars) in about a year.
A student uses a telescope for the first time at Kalinga Primary School in northern Tanzania. Credit: Telescopes to Tanzania/Indiegogo
If you have a dollar to spare, why not share it? That’s the attitude that Astronomers Without Borders is encouraging people to adopt as it talks about contributing to a Tanzanian campaign to increase astronomy education in the African country.
There’s a crowdfunding campaign on right now to build a Center for Science Education and Observatory. With 23 days to go, 18% of the needed $38,000 has already been raised.
“The highly successful program Telescopes to Tanzania, of the international non-profit organization Astronomers Without Borders, has been actively supporting the East African nation’s schools since 2011. Tanzanian students are without textbooks and many basic educational resources we take for granted in western countries. Teacher training in science is often lacking,” the Indiegogo page reads.
“Now we are building The Center for Science Education and Observatory in East Africa to provide training for teachers, hands-on laboratories, an astronomical observatory, and quality educational resources that will all have a long-lasting impact nationwide.”
Once the center is ready, the campaign pledges it will be able to sustain itself through activities such as astro-tourism.
Artist's impression of the Stardust spacecraft. Credit: NASA/JPL-Caltech
If the scientists are right, a NASA spacecraft brought stuff from outside the solar system back to Earth. The Stardust spacecraft, which was originally tasked with chasing after Comet Wild 2, brought our planet seven grains that look fluffier than expected.
While the scientists say that more tests are needed to determine these particles originated from outside the solar system, they are confident enough to publish a paper on the findings today.
“They are very precious particles,” stated Andrew Westphal, a physicist at the University of California, Berkeley’s space sciences laboratory who led 65 co-authors who created a paper on the research.
What’s more, the findings came with a big assist from volunteers who participated in a crowdsourced project to look at dust tracks in Stardust’s aerogel detector.
The Stardust spacecraft was launched in February 1999 to gather samples of Comet Wild 2 and return them to our planet. Stardust also attempted to collect interstellar dust twice in 2000 and 2002 for 195 days. Its mission was extended in 2011 to look at Comet Tempel-1, the comet that Deep Impact crashed into.
The sample return capsule, however, separated from the spacecraft in January 2006 as planned while Stardust flew by our planet, landing safely on Earth. Comet samples and interstellar samples were stored separately. Scientists then began the work of seeing what the spacecraft had picked up.
An electron scanning microscope image of an interstellar dust impact on the Stardust spacecraft. The crater is 280 nanometers across. Residue from the dust particle is barely visible in the center. Credit: Rhonda Stroud, Naval Research Laboratory
Here’s where the volunteers came in. These people, who called themselves “Dusters”, participated in a project called Stardust@home that put more than a million images online for people to examine.
Three particles, dubbed “Orion”, “Hylabrook” and “Sorok”, were found in the aerogel detectors after volunteers discovered their tracks. (Many more tracks were discovered, but only a handful led to dust. Also, 100 tracks and about half of the 132 aerogel panels still need to be analyzed.)
Four more particles were tracked down in aluminum foils between the aerogel tiles. That wasn’t originally where they were supposed to be collectors, but despite their “splatted” and melted appearance there was enough left for scientists to analyze. (About 95% of the foils still need to be examined.)
One of the two largest specks found in the Stardust spacecraft that are suspected interstellar dust. This containned olivine, spinel, magnesium and iron. Credit: Westphal et al. 2014, Science/AAAS
So what did the scientists see? They describe the particles as fluffy, sometimes appearing to come from a mix of particles. The largest ones included crystalline material called olivine (a magnesium-iron-silicate). More testing is planned to see what their abundances of different types of oxygen are, which could help better understand where they came from.
Additionally, three of the foil particles had sulfur compounds, which is controversial because some astronomers believe that isn’t possible in interstellar dust particles.
The research was published in the journal Science. Twelve more papers on Stardust will be published in Meteoritics & Planetary Science.
Rubble piles are common among asteroids, as illustrated by this artist's conception of 2011 MD. Credit: NASA/JPL-Caltech
How do asteroids hold their rubble piles together? Previously, scientists said it was a combination of friction and gravity. But new observations of asteroid 1950 DA reveals something else is at work. The asteroid is rotating too quickly for gravity to keep it together, so what’s going on?
“We found that 1950 DA is rotating faster than the breakup limit for its density,” stated Ben Rozitis, a postdoctoral researcher at the University of Tennessee, Knoxville who led the research. “So if just gravity were holding this rubble pile together, as is generally assumed, it would fly apart. Therefore, interparticle cohesive forces must be holding it together.”
Image of asteroid 1950 DA. Credit: NASA
Cohesive forces refer to the act of individual molecules or particles sticking together. It’s the first time scientists have found this in action on an asteroid. Better yet, if confirmed in other asteroids this has implications for protecting Earth from a killer asteroid should one come our way.
If the threat turns out to be a loosely held together asteroid, an impact in just the right spot would break the single asteroid into many. (Of course, you’d want to make sure that the problem doesn’t end up turning into multiple smaller asteroids hitting Earth instead of a single large one.)
Now the researchers are interested in knowing if cohesive forces are also in action on Comet 67P/Churyumov–Gerasimenko — the comet being examined by Rosetta right now and in November, by the lander Philae.
A Hubble Space Telecope picture of globular cluster IC 4499. The new observations showed that it is about 12 billion years old, contrary to previous observations showing a puzzling young age. Credit: European Space Agency and NASA
Is this group of stars belonging to one generation, or more? That’s one of the things that was puzzling astronomers for decades, particularly when they were trying to pin down the age of IC 4499 — the globular cluster you see in this new picture from the Hubble Space Telescope.
“It has long been believed that all the stars within a globular cluster form at the about same time, a property which can be used to determine the cluster’s age,” stated information from the European Space Agency reposted on NASA’s website.
“For more massive globulars however, detailed observations have shown that this is not entirely true — there is evidence that they instead consist of multiple populations of stars born at different times.”
IC 4499 is somewhere in between these extremes, but only has a single generation of stars — its gravity wasn’t quite enough to pull in neighboring gas and dust to create more. Goes to show you how important it is to re-examine the results in science.
A Soyuz spacecraft on the International Space Station (front) above the lights of Europe. Picture taken during Expedition 40. Credit: Reid Wiseman/Twitter
A lot of action happens on Earth at night! Just ask NASA’s Reid Wiseman, a prolific picture-tweeter who recently uploaded a series of images of night lights shining all around the world.
From his perch on the International Space Station, Wiseman sent pictures showing borders from space, that glowing punch in the desert landscape that is Dubai, and clouds rolling in over the bright lights of Los Angeles. Check out some samples below the jump.
Actor Robin Williams rose to international fame in the 1980s playing the role of an alien, Mork, in the sitcom Mork & Mindy. Credit: ABC/YouTube (screenshot)
The second man to walk on the moon spoke again about his struggles with depression after actor Robin Williams, 63, died Monday of an apparent suicide. Apollo 11 astronaut Buzz Aldrin urged compassion, and said those with the illness should have access to all the resources needed for treatment.
“I regarded Robin Williams as a friend and fellow sufferer. His passing is a great loss,” Aldrin wrote on his Facebook page yesterday (Aug. 12).
“The torment of depression and the complications of addiction that accompany it affect millions, including myself and family members before me – my grandfather committed suicide before I was born and my mother the year before I went to the moon – along with hundreds of veterans who come to a similar fate each year. As individuals and as a nation we need to be compassionate and supportive of all who suffer and give them the resources to face life.”
Williams rose to international fame in the 1980s after playing an alien Mork (from the planet Ork) on the sitcom Mork & Mindy. He also was noted for his roles in the movies Mrs. Doubtfire, Aladdin and Good Will Hunting, among many others. After his death was made public, NASA posted a link to Twitter of this video (below) of Williams giving a wake-up call to space shuttle crew STS-26 in 1988 in the style of his Army DJ character in Good Morning, Vietnam.
If you’re facing depression, mental health services are available in most jurisdictions to give you help. Across the United States, for example, you can contact the National Suicide Prevention Lifeline on its website or by phone, 1-800-273-TALK (1-800-273-8255).
A view of the nucleus of Comet 67P/Churyumov–Gerasimenko taken by the Rosetta spacecraft Aug. 11, 2014. Credit: ESA/Rosetta/NAVCAM
Mark your calendars, astronomy geeks: exactly one year from today, the comet the Rosetta spacecraft is chasing will make its closest approach to the Sun. As Comet 67P/Churyumov–Gerasimenko draws closer to the star, the radiation pressure will cause gas, ice and dust to stream off the comet in ever greater quantities, scientists expect.
But that process is already starting. Preliminary measurements by a dust detector aboard the Rosetta spacecraft show that dust is at least as frequent — or perhaps even more abundant — than what models have predicted. Meanwhile, as reported on Universe Today earlier this week, Rosetta’s COSIMA instrument is also doing dust measurements.
Rosetta’s Grain Impact Analyser and Dust Accumulator (GIADA) has already detected four dust grains on its impact sensor. The detections took place between Aug. 1 and Aug. 5 at various distances as Rosetta approached the comet, starting from as far as 814 kilometers (506 miles) to as close as 179 kilometers (111 miles). Rosetta arrived at the comet on Aug. 6.
The first impact was just a tad higher than the detection limit for GIADA, scientists said. They also estimated how big the grains are based on how quickly they crash into the impact detector — anywhere from tens of microns (the width of a human hair) to a few hundreds of microns across.
While the results are scientifically interesting, the European Space Agency pointed out that they will also have practical use.
An artist’s impression of the Grain Impact Analyser and Dust Accumulator (GIADA) on the Rosetta spacecraft, which is collecting dust from Comet 67P/Churyumov–Gerasimenko. The inset is a an analog dust grain used in the laboratory to calibrate the instrument. Credit: ESA/Rosetta/GIADA/Univ Parthenope NA/INAF-OAC/IAA/INAF-IAPS
A lander called Philae is expected to touch down on the comet in November, so dust predictions will help planning for that. And for Rosetta itself, knowing the dust environment can help protect the spacecraft from strikes.
“GIADA will also provide inputs to other instruments on-board Rosetta, and will help improve coma dust models in support of the Philae landing operations,” ESA stated.
“Furthermore, GIADA will play an important role for the health and the safety of Rosetta and its instruments, providing information about the deposition rates of dust on optical components and critical parts of the spacecraft, such as the solar panels.”
ESA added that the grains themselves are likely a mixture of silicates, organics and some other stuff. Ice from the nucleus surrounds the grains, and the ice itself becomes a gas when the Sun warms the comet. Dust surrounds the comet in a coma and as it gets closer to the Sun, it streams out as a tail.
Clouds swirl near Titan's north pole in this annotated still image from the Cassini mission. Credit: NASA/JPL-Caltech/Space Science Institute
Swoosh! At long last, and later than models predicted, clouds are starting to appear on Titan’s nothern hemisphere. The region is just starting to enter a seven-year-long summer, and scientists say this could be an indication of coming summer storms there.
This moon of Saturn is of particular interest to astrobiologists because it has hydrocarbons (like ethane and methane), which are organic molecules that are possible precursors to the chemistry that made life possible. But what is also neat about Titan is it has its own weather system and liquid cycle — which makes it closer to Earth than to our own, nearly atmosphere-less Moon.
“The lack of northern cloud activity up til now has surprised those studying Titan’s atmospheric circulation,” wrote Carolyn Porco, the imaging lead for Cassini, in a message distributed to journalists.
“Today’s reports of clouds, seen a few weeks ago, and other recent indicators of seasonal change, are exciting for what they imply about Titan’s meteorology and the cycling of organic compounds between northern and southern hemispheres on this unusual moon, the only one in our solar system covered in liquid organics.”
Clouds swirl near Titan’s north pole in this annotated still image from the Cassini mission. Credit: NASA/JPL-Caltech/Space Science Institute
The pictures were taken by the Cassini spacecraft, which has been orbiting Saturn and its moons since 2004. The satellite arrived at the system in time to see clouds forming in the southern hemisphere, but the moon has been nearly bereft of clouds since a large storm occurred in 2010.
This particular cloud system occurred over Ligeia Mare, which is near Titan’s north pole, and included gentle wind speeds of about seven to 10 miles per hour (11 to 16 kilometers per hour.)
The sequence takes place between July 20 and 22, with most of the pictures separated by about 1-2 hours (although there is a 17.5-hour jump between frames 2 and 3.)
