Watch billions of tons blast out from the surface of the Sun
This composite image from SOHO and SDO shows this plume of solar plasma belching out from the Sun on August 12, 2015. Credit: NASA/ESA
Friday, August 14, 2015, 4:10 PM - Watch billions of tons of solar matter lash out towards the Earth, a big outburst from Comet 67P on its closest approach to the Sun, and Mars rover Curiosity looms over us in its latest selfie! It's Science Pics of the Week!
Aurora watchers be on alert!
On the night of Tuesday, August 11, a massive plume of solar matter belched out from the Sun, followed by a what is known as a "filament eruption" - when a thin rope of cooler solar matter tears away from the surface and is flung out into space.
NASA and the European Space Agency's Solar and Heliospheric Observatory (SOHO) caught the whole thing on its cameras.
SOHO's view of the Sun, from August 12, 2015. All times shown in UTC. Credit: NASA/ESA
This animation combines the views from both of the spacecraft's LASCO (Large Angle Spectrometric Coronagraph) instrument - the red C2 close-up and the blue C3 wide-field - to show the progression of the events. The "blank" region at the centre of the animation is the instrument's occulter disk, which is used to physically block out the brightest light from the Sun's disk, so that the instrument can pick up the coronal streamers and coronal mass ejections.
What will all this mean for us here on Earth? Although the majority of the eruption is headed off away from us, according to projections from NOAA's Space Weather Forecast Center, it appears as though the very edge of the CME will sweep past Earth this weekend.
NOAA plasma density solar wind forecast, from August 11 through 18, 2015. Credit: NOAA SWPC
This has forecasters calling for G1 geomagnetic storm conditions on Sunday, with the best times to check for auroras being in the hours before sunrise for the western half of Canada, and after dark, Sunday evening, for eastern Canada.
Comet outburst during its "Day in the Sun"
Comet 67P/Churyumov-Gerasimenko - the same comet that the ESA's Rosetta spacecraft has been orbiting around since last September - made its closest pass to the Sun this week, and it put on quite a good show as it did.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
According to the ESA's Rosetta blog:
"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," says Nicolas Altobelli, acting Rosetta project scientist.
Rosetta’s measurements suggest the comet is spewing up to 300 kg of water vapour - roughly the equivalent of two bathtubs - every second. This is a thousand times more than was observed this time last year when Rosetta first approached the comet. Then, it recorded an outflow rate of just 300 g per second, equivalent to two small glasses of water.
Along with gas, the nucleus is also estimated to be shedding up to 1000 kg of dust per second, creating dangerous working conditions for Rosetta.
The spacecraft has backed off to over 300 kms away from the 67P/C-G during this active period, but continues to monitor the comet's activity from afar.
Curiosity looms big in latest Mars selfie
NASA's Mars Curiosity rover has taken a selfies before, but none quite like this one.
Credit: NASA/JPL-Caltech/MSSS/Kevin M. Gill, courtesy Curiosity Tumblr account
The image is still a composite - many smaller images taken by the MAHLI instrument, at the end of the rover's arm, and then stitched together to form the nearly completed view. However, the team changed up the angle, essentially giving us Mars' point of view on the rover, and they are showing off the source of the images.
Also, in all (or nearly all) the previous selfies, the pattern the rover used to take the images was carefully planned so as to ensure that its arm (and any shadows cast by it) would not interfere with the final picture. In this one, the base of the arm is visible, as well as the shadow of the bulky APXS/MAHLI instrument cluster at the end of the arm.