White House Budget Proposal for NASA Includes a Mission to Europa
Planetary scientists are thrilled, to say the least, that the White House’s 2016 Budget Proposal for NASA includes funding for a mission to Jupiter’s watery moon Europa. The President’s budget request for $18.5 billion is a half-billion more for NASA than it received in 2015. Aside from the Europa mission, there is also support for a 2022 ESA-led mission to Jupiter’s icy moons, for which NASA is developing some instruments.
But wait, there’s more! The Mars 2020 mission received a boost of up to $228 million, $50 million was allocated for near-Earth object research to identify candidates for a future asteroid redirect mission, and funding was also set aside for the Transiting Exoplanet Survey Satellite (TESS), the successor to the amazingly-successful Kepler mission. NASA is also directed to keep the James Webb Space Telescope on track for a 2018 launch, and to continue development of the mammoth Space Launch System, which will eventually launch the Orion Multi-Purpose Crew Vehicle into deep space, as well as to provide ongoing support for the Commercial Crew Program, enabling private companies (such as Boeing and SpaceX) to develop systems capable of launching astronauts into space.
On the other hand, alongside the budget proposal’s additions are some glaring omissions. No funding is indicated for missions that are still operational—for example, the Lunar Reconnaissance Orbiter and the long-lived Opportunity Mars rover.
All in all, however, for the funding given to forward-looking planetary science such as the Europa mission and continuing support for commercial spaceflight development, observers look favorably on this proposal, hopeful that nothing will be lost in the process of congressional counter-proposal and compromise. With the recent changes in congressional leadership and budgetary oversight, nothing is guaranteed until the dust settles. -Bing Quock
“GoreSat” to Fly, Falcon to Land?
This Sunday morning, if all goes well, Space Exploration Technologies (SpaceX) will launch a NOAA satellite called the Deep Space Climate Observatory (DSCOVR), the reincarnation of the “Triana” satellite envisioned by former Vice President Al Gore in 1998 for the purpose of providing an inspiring, continuous, realtime view of Earth via the Internet.
Although fully built, Triana (also dubbed the “GoreSat”) was cancelled and put in storage in 1999 over questions regarding its scientific value. However, the aging satellite was recently dusted off, renamed, and repurposed as a solar observatory, and will be SpaceX’s first launch to L1—a point about 1.5 million kilometers (930,000 miles) away on Earth’s sunward side, where the gravitational pulls of both Earth and the Sun are equal, allowing a satellite at that location to orbit the Sun with exactly the same period as Earth. From there, it will be able to make continuous observations of both the Sun and the fully-illuminated side of Earth, its distance allowing it to see the entire planet, unlike weather satellites in geosynchronous orbit, which only see a portion of the globe. Four spacecraft have previously been launched to this location by NASA and ESA.
This launch will also be used to attempt, once again, to land the first stage of the Falcon 9 rocket on SpaceX’s Autonomous Spaceport Drone Ship, a GPS-guided, football field-size barge (whimsically christened “Just Read the Instructions”) that serves as the landing pad for SpaceX’s attempts at a rocket-powered touchdown. Having demonstrated the ability to bring the spent rocket stage back to a pinpoint return in its previous launch to the International Space Station, SpaceX is eager to repeat the feat, albeit more successfully. With at least a dozen flights scheduled over the coming year, SpaceX has plenty of chances to keep trying to get it right. -Bing Quock
Mini-Neptunes and Habitable Evaporated Cores
When looking for life elsewhere in our galaxy, M dwarf stars are a good place to start. They’re abundant, which means we have plenty to choose from in making our observations. And they’re small, which means that the habitable zone—or region in which liquid water can exist on the surface of an Earth-ish-sized planet—will be close to the star, making those planets easier to spot.
Two upcoming missions are set to detect such worlds: the Transiting Exoplanet Survey Satellite (TESS) and repurposed Kepler spacecraft (K2) will look for potentially habitable planets around M dwarfs in the coming years. So it might be helpful to know what to look for, and according to a paper in last month’s Astrobiology, the answer could be “habitable evaporated cores.”
Rodrigo Luger of the University of Washington and his colleagues believe that mini-Neptunes—planets that typically form far from their host star, with ice molecules joining with hydrogen and helium gases in great quantity to form icy-rocky cores surrounded by massive gaseous atmospheres—could hold the original ingredients for life to form around a slight, dim M dwarf.
“They are initially freezing cold, inhospitable worlds,” Luger says. “But planets need not always remain in place. Alongside other processes, tidal forces [the star’s gravitational pull on a planet] can induce inward planet migration.” This process can bring mini-Neptunes into their host star’s habitable zone, where they are exposed to much higher levels of X-ray and ultraviolet radiation.
This can, in turn, lead to rapid loss of the atmospheric gases to space, sometimes leaving behind a hydrogen-free, rocky world smack dab in the habitable zone. Voilà! A habitable evaporated core!
“Such a planet is likely to have abundant surface water, since its core is rich in water ice,” Luger says. “Once in the habitable zone, this ice can melt and form oceans,” perhaps leading to life. -Molly Michelson
Meteorite May be 4.4 Billion Year Old Martian Crust
While no mission has ever returned a physical sample of Mars back to Earth, scientists are fortunate enough to possess a few pieces of the Red Planet delivered here in the form of meteorites. One of these, NWA 7034, nicknamed “Black Beauty,” was uncovered in Morocco in 2011. Its chemical makeup reveals that it is not only a cast off from Mars, but it’s also older and different from any Martian meteorite ever found. A new report suggests it may actually be our only sample of a 4.4 billion-year-old fragment of the Martian crust.
The meteorite itself is a 320-gram (11-ounce) piece of Martian breccia, a mash up of different rock types welded together in a dark basaltic matrix. Spectrographic studies of the meteorite, compared to data gathered by crafts orbiting Mars itself, indicate the chunk of rock is a close match to (and may help explain) a certain region of Mars known as the dark plains.
Mars is well known for its distinctive reddish color. However, the “rust” layer of Mars isn’t much more than a thin layer of dust and is almost non-existent in certain areas, where dark plains reveal the dark-colored crust beneath. So, while unique for our samples, Black Beauty may be more representative of the “bulk background” of rocks composing the Martian crust, says Kevin Cannon, a Brown University graduate student and lead author of the new paper.
The team also notes that it would make sense for much of Mars’s crust to be composed of dark breccia like this meteorite. Materials similar to it are produced by large impacts and there are over 400,000 impact craters on the Martian surface more than one kilometer (about six-tenths of a mile) in diameter. “This is showing that if you went to Mars and picked up a chunk of crust, you’d expect it to be heavily beat up, battered, broken apart and put back together,” Cannon said. -Elise Ricard
Image: Rodrigo Luger/NASA images