Rosetta Gets Some Sun as Things on 67P Heat Up [PHOTOS]
The historic spacecraft Rosetta and its comet host are closer to the Sun than ever before, and that means one thing: breathtaking photos.
Above is a series of images consecutively snapped by the Rosetta spacecraft's OSIRIS narrow-angle camera on 12 August 2015, just a few hours before the comet reached the closest point to the Sun along its 6.5-year orbit. The moments closing up to this point - called the perihelion - were expected to deliver some stunning imagery, and they certainly delivered.
But what exactly are we seeing here? Why does it seem that Rosetta's host comet, 67P/Churyumov-Gerasimenko, is lit up like a roman candle? According to the ESA, those rays reaching out from the comet are clouds of gas and steam, which continue to escape at greater and greater rates from the rubber-ducky-shaped ice-ball.
NASA has already reported that 67P is melting much faster than it was last year, largely because the comet is drawing ever-closer to our Sun in a wide-but-spiraling orbit. It will soon grow too hot even for the Rosetta spacecraft to stand, and the primary stage of this historic mission will come to an end.
Around the peak of the perihelion, the comet reportedly burst outward with what can only be described as "jets of steam" breaking through the comet's surface of ice and dust. (Scroll to read on...)
"Activity will remain high like this for many weeks, and we're certainly looking forward to seeing how many more jets and outburst events we catch in the act, as we have already witnessed in the last few weeks," Nicolas Altobelli, the acting Rosetta project scientist, said in a recent statement.
Rosetta's measurements suggest the comet is spewing up to 300 kg of water vapor - roughly the equivalent of two bathtubs - every second. For comparison, when Rosetta first approached 67P last year, near the halfway point between Jupiter and Mars, the comet was only 'sweating' about two cups of water a second.
The comet is also shedding quite a lot of dust - up to 2200 pounds (1000 kg) per second. Clouds of dust, rocks, and ice burning up in Earth's atmosphere are traditionally what cause meteor showers. However Rosetta doesn't have the luxury of an atmosphere to protect it.
"In recent days, we have been forced to move even further away from the comet," explained Sylvain Lodiot, the ESA's spacecraft operations manager. "We're currently at a distance of between 325 km and 340 km this week, in a region where Rosetta's startrackers can operate without being confused by excessive dust levels - without them working properly, Rosetta can't position itself in space." (Scroll to read on...)
The comet's surface has also seen some impressive temperature spikes, reaching up to a few tens of degrees above absolute zero. That's a stunning revelation, as initial Rosetta analyses had shown 67P at a chilly -70 degrees Celsius.
"We aim to go back in much closer again after the activity subsides and make a survey of how the comet has changed," Altobelli added.
The hope, he explained, is to make use of both Rosetta's long-range observations and data from Philae, the wayward lander that is currently hiding in a dark cranny on 67P. With limited sunlight reaching the solar-powered robot, the fate of its mission has been in question ever since its historic landing last Nov.
"We continue to hope that Philae will be able to resume its scientific operations on the surface and give us a detailed look at changes which may be occurring immediately surrounding its landing site," Altobelli said.
"It's exciting to reach the milestone of perihelion," added mission manager Patrick Martin, "and we look forward to seeing how this amazing comet behaves as we move away from the Sun with it over the coming year."
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