As viewed from the European Space Agency’s Rosetta spacecraft, Comet 67P/Churyumov-Gerasimenko sprays out gas just twelve hours before its closest approach to the sun (on this pass.) From Astronomy Picture of the Day, 15/8/15.
Pecdant’s corner:- USian alert? The APOD page says the comet’s primordial ices are sublimating. That would be subliming, then. In my understanding to sublimate is to suppress or divert an instinct.
This isn’t a view any human of even the relatively recent past could ever have seen: the Moon passing in front of the Earth:-
From Astronomy Picture of the Day 7/8/15, this photo – taken by NASA’s Deep Space Climate Observatory (DSCOVR) spacecraft – is captioned Full Moon, Full Earth, but of course it’s a New Moon; from the surface of the Earth all of the Moon would appear dark. The hemisphere of the Moon seen in the photo is of course its far side (which isn’t dark, except briefly: it gets as much sunlight as the near side does, only in reverse proportion.)
The DSCOVR spacecraft is situated at the Earth-Sun L1 Lagrange Point (see diagram – not to scale – below) where the orbit of a satellite is stable. As such it is perfectly placed to observe the Moon transit the Earth as above, which from its perspective occurs twice a year.
I tried to photograph the pinhole camera image I managed to get of yesterday’s eclipse. It was difficult to focus the digital camera on the image made by the pinhole, though. In real life it appeared much sharper.
Not that it’s told me much I didn’t know but the hunt for supernovae they mentoned at the zooniverse site was intriguing. Apparently humans are required to check the comparison photos of patches of sky after the before and after subtraction has been made; computers can’t do it.
Up to when I looked just now over 26,000 people have taken part in the effort and over 1,000,000 comparisons have been checked. Out of these tonight’s programme said they’d found one supernova already.
There has been a lot about tomorrow’s solar eclipse in the two programmes so far. In the morning I’ll be out with my two pieces of card pinhole camera trying to image it. As I recall the percentage coverage for the last solar eclipse I witnessed (in 1999) was less than the 95 or so for my area tomorrow. I doubt I’ll see another.
Posted in Astronomy at 12:00 pm on 26 November 2014
A movie showing liquid on the surface of a world other than Earth?
Yes indeed. This is Saturn’s moon Titan and its methane/ethane lakes in a digital compilation of still radar images from NASA’s Cassinni satellite. The liquid is deep blue, the higher land tan coloured.