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The Comet Sublimes

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.

APOD 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.

Moon’s Transit of Earth

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:-

Full Mooon, Full 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.

Earth-Sun Lagrange Points

Pluto Flyby

It hasn’t taken NASA long to get this New Horizons flyby sequence of Pluto up on You Tube:-

And on Astronomy Picture of the Day on 17/7/15 was this photo of Pluto’s largest moon Charon.


Wonderful stuff.

Every single time spaceprobes have gone to somewhere as yet unexplored they have yielded unexpected results. This time the youth of Pluto’s surface was a surprise.

Astronomy Picture of the Day (APOD)

Astronomy Picture of the Day was 20 years old on Jun 16th. It has been on a bit of a roll recently.

The Pinwheel Galaxy (Jun 14th):-

Pinwheel Galaxy

The Black Eye galaxy (Jun 18th):-

the black eye galaxy

On 23rd Jun there was this star bubble round Sharpless 2-308:-

Star Bubble

This is a picture of Zeta Ophiuchi (Jul 5th) which is travelling to the left at 24 kilometres per second thus causing the bow-shock in the interstellar dust as shown:-

Zeta Ophiuchi

The next day gave us this picture of clouds near Rho Ophiuchi

Clouds near Rho Ophiuchi

Then Jul 8th had this stunning scene of Dione, Saturn and Enceladus (Saturn is visible only as a faint arc and its rings are edge-on):-


Fly-over Ceres, Jun 10th, a composite of still pictures:-

It’s exciting times for NASA as New Horizons is getting very close to Pluto. See yesterday’s picture:-

5 million miles from Pluto

Wonderful stuff.

Fly Past of Ceres

Images of dwarf planet Ceres, taken from NASA’s Dawn spacecraft and made into a movie. (Via Astronomy Picture of the Day, 10/6/15.)

Pinhole Eclipses

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.

I did get multiple images by using a colander:-

I’ll stick to the day job.

Stargazing Live Hunting Supernovae

I’ve been watching BBC 2’s Stargazing Live the past two nights.

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.

An Asteroid with a Moon!

Apparently on Monday an asteroid passed very close to the Earth-Moon system, just over three times the Earth-Moon distance away. NASA’s Deep Space Network antenna array tracked it by radar.

There’s a video of this on the JPL site. The moon is clearly visible. Astounding stuff.

I found this via Astronomy Picture of the Day.

Titan’s Lakes

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.

The video featured on Astronomy Picture of the Day on 24/11/14.

The Heart of the Comet*

Okay, so the harpoons didn’t fire and the lander bounced twice, but to set down on a comet is a stunning achievement.

Philae on 67P/Churyumov-Gerasimenko

(Pinched from the Daily Galaxy, picture from ESA/Rosetta/Philae)

*Not quite; but I couldn’t resist.

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