Using data gathered by ESA’s Venus Express researchers have determined what likely happened to Venus’ water: it was “zapped” away by a surprisingly strong electric field generated by the planet’s atmosphere and the incoming solar wind. Without a protective magnetosphere like Earth has, Venus’ upper atmosphere directly interacts with energetic particles streaming out from the Sun. The result is an electric field that’s at least five times more powerful* than those that might exist on Earth or Mars, strong enough to strip away oxygen ions—one of the two key ingredients for water.
It’s truly an electrifying discovery. (When you’re done groaning, read on…)
Captured by the EU’s Copernicus Sentinel-3A satellite on Feb. 29, 2016, this beautiful composition of blacks, purples, and blues shows the twilight transition across the Norwegian archipelago of Svalbard, located north of the Arctic Circle between Norway and the North Pole. The snow-covered and fjord-cut large island of Spitsbergen can be seen at the right edge, while sea ice and clouds follow their own swirling currents on and above the Greenland sea.
This is the first image acquired by the spacecraft, which was launched aboard a converted-ICBM Rockot vehicle on Feb. 16 from Russia’s Plesetsk Cosmodrome. The first of two planned Sentinel-3 satellites, 3A is currently in a high-inclination orbit at an altitude of 505 miles (814 km).
ESA’s Philae lander, the first spacecraft to successfully soft-land on the surface of a comet and former piggyback partner to Rosetta, has not been in communication since July of 2015. With 67P now six months past perihelion and heading deeper out into the Solar System and Rosetta’s mission coming to a close this year, it’s not likely that Philae will ever be heard from again.
Ever since we got our first good look at Comet 67P/Churyumov-Gerasimenko from the approaching Rosetta spacecraft in 2014 it has been considered to be a textbook example of a contact binary, with its “rubber duckie” double-lobed shape consisting of an oval “head” and flat-bottomed “body” joined by a “neck.’ Now, using data gathered by Rosetta’s OSIRIS instrument while in permanent orbit, scientists are certain that this is indeed the case: 67P/C-G as we see it today was created by the slow-speed collision of two separate comets, each once an independent and fully-formed object in its own right (and not, as the alternate hypothesis suggested, via the gradual erosion of a once-larger single object.)
Read more about these findings and how they were determined on ESA’s Rosetta site here.
On July 29, with ESA’s Rosetta spacecraft in orbital tow, the 2.5-mile (4-kilometer) -long Comet 67P/Churyumov-Gerasimenko fired its brightest jet yet since Rosetta’s arrival just over a full year ago, on Aug. 6, 2014.
Most of the images of 67P showing jets and outgassing activity released over the past few months have been edited to boost jet visibility but this recent flare-up needed no such enhancement. Rosetta’s high-resolution OSIRIS camera had no problem capturing the brief ice capade from 115 miles (186 km) away.
ESA’s comet-chasing Rosetta mission is best known today for its two historic firsts of entering orbit around a comet and sending a lander onto the surface of said comet, in May and November of 2014 respectively. But Rosetta didn’t just go directly from its March 2, 2004 launch to comet 67P; it had to perform several flyby maneuvers beforehand with planets and asteroids on its way out to meet a comet. And now, ESA has shared many of the images acquired during those close passes during its cruise phase in a series of online albums for the public to easily access.
The image above shows the Moon beyond the hazy line of Earth’s atmosphere, acquired on March 4, 2005 during Rosetta’s first gravity-assist flyby of Earth just over a year after its launch. (Rosetta made three such passes by our planet before gathering enough velocity to make it out to 67P!)
See a list of Rosetta’s flybys below and find out how to access the albums.