What's Up In Space? Rosetta comet waking up, Milky Way dark matter and Mars milestones
Wednesday, February 11, 2015, 11:03 AM - What's in store this week on What's Up In Space?
Rosetta sends back amazing pictures of a waking comet, researchers track stars to locate dark matter, and our Mars explorers are racking up some impressive milestones.
Comet 67P gets a wakeup call from the Sun
February 6, 2015
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Comet 67P/Churyumov-Gerasimenko still has a fair distance to cover before it gets to its closest point to the Sun, but the comet is already waking up, blasting out jets of gas, water vapour and dust. These three images, snapped by the ESA's Rosetta spacecraft, which has been orbiting the comet since last August, were taken on three separate days, showing these jets from different angles.
The comet will grow much more active as 2015 progresses, and these jets will not only grow, but multiply, sending out enough gas and dust to form into the comet's atmosphere (or 'coma') and its tails. From here, the coma will completely obscure the nucleus of 67P, but Rosetta will capture everything from close up, so we won't miss a thing.
The dark core of the Milky Way
We're in the minority in our universe. The matter we're made up of (and which makes up pretty much everything we can see) - normal matter - only represents about 5 per cent of the total mass and energy of the universe. There's something else out there - something we can't see or detect, since it doesn't emit any light or radiation - that makes up far more of the universe. That's what researchers call 'dark matter'. It's a frustrating search, for sure. How can you find something like that?
Red markers indicate stars moving away from us, while blue are stars moving towards us. The large blue halo is the estimated distribution of dark matter in the galaxy. Credit: Iocco et al./Nature/Serge Brunier/NASA
Fortunately, all matter - normal or dark - has mass, and if something has mass it affects the universe in some way, through its gravity. Astronomers in Europe have taken advantage of this to search for evidence of dark matter right here in the Milky Way, and they believe they've found what they're looking for, by watching the speeds at which stars orbit in our galaxy.
According to study coauthor Miguel Pato, from Stockholm University:
"In our new study, we obtained for the first time a direct observational proof of the presence of dark matter in the innermost part of the Milky Way. We have created the most complete compilation so far of published measurements of the motion of gas and stars in the Milky Way, and compared the measured rotation speed with that expected under the assumption that only luminous matter exists in the Galaxy. The observed rotation cannot be explained unless large amounts of dark matter exist around us, and between us and the Galactic centre."
For being completely uninhabited (at least to our knowledge), Mars is a fairly busy place. There's two rovers rolling around on its surface and four satellites currently conducting science from orbit.
These tireless robots send a near-continuous stream of amazing data and images back to Earth, and when they reach an important milestone, it's worth it for us to pause and recognize their efforts.
40,000 orbits and still going
The Mars Reconnaissance Orbiter, NASA's 'eye in the sky' for Martian terrain and geology, has been circling the Red Planet since March of 2006, and on February 7, 2015, it completed its 40,000th orbit of the planet! It takes time to sift through and process the images MRO takes, so images from that day aren't yet available, but it captured this incredible view of wind-formed features with its HiRISE camera on January 4.
Opportunity nears 'marathon' distance
NASA's longest-running mission on the surface of Mars is the Opportunity rover, which just celebrated its 11th anniversary on January 25, 2015. Now, it's coming up on another mission milestone, as it closes in on a total roving distance of 42.195 kilometers (the official distance of an Olympic marathon race).
Credit: NASA/JPL-Caltech/Univ. of Arizona
According to NASA:
In this image, north is up. The southern end of the solid blue line indicates the rover's position after a drive on Sol 3926, the 3,926th Martian day of Opportunity's work on Mars (Feb. 9, 2015). The rover team plans to drive Opportunity near or into "Spirit of St. Louis Crater" before the rover enters Marathon Valley. This area is all part of the western rim of Endeavour Crater.