The Moon/Venus/Jupiter conjunction as no-one on Earth saw it

Recently there was a conjunction of the crescent Moon, Venus (also in crescent phase) and Jupiter.

It was captured by US Astronaut Scott Kelly, currently Commander of the International Space Station, with another planet added in—Earth!

Day 114. #Moon #Venus #Jupiter...#Earth Good night from @space_station! #YearInSpace pic.twitter.com/GsOxOKt34S

— Scott Kelly (@StationCDRKelly) July 19, 2015

It's rare for photos from the ISS to also feature the starfield background. There is just so much ambient light from Earth that it drowns out the fainter stars for photos. Unless you take one photo exposed for the Earth and another exposed for the stars, and combine them in Photoshop. But even then it's very hard not to have the Earth blowing out the stars where they are very close to each other.

NASA has been know to add in the relevant starfield from a completely different shot. And there's nothing wrong with that—our eyes see a much broader range of light than a camera can capture in one shot. So it's just using tools available to more closely represent what the astronauts themselves are actually seeing.

Which all makes the timing on this shot all the more wonderful to have achieved. But then, he is orbiting Earth every 79 minutes, so he probably had a few chances to get it right!

Kelly is well worth following on Twitter—he posts some great material from his unique perspective. Such as:

Take a tour of dwarf planet Ceres

Enigmatic bright spots within a crater on Ceres. Photo by NASA JPL on 6 June 2015 at 4400 kilometres altitude,
Resolution 410 metres per pixel.

NASA's Dawn robot entered orbit around dwarf planet Ceres on 6 March 2015.

It's the first spacecraft to visit two distinct interplanetary bodies, after first spending 14 months studying the smaller dwarf planet Vesta in 2011 and 2012.

The Dawn mission team are currently performing mapping orbits at around 13,600 kilometres out and navigational imaging about 5100 kilometres out. Once complete, Dawn will start edging into closer orbits.

NASA has combined images from these orbits to date into this wonderful flyover video released on 8 June:


At 15 seconds in, you'll see the mysterious bright spots (see photo above) in the base of a medium-sized crater that have so intrigued people the world over since they were first imaged months ago as Dawn approached Ceres. Nasa scientists are wondering if it could be a volcano, a geyser or cryo-volcano, shiny rock (as in glassy like molten from an impact), ice or salt.

Oh my. This puts it all in perspective wonderfully...

So just how big is the Sun?

Pretty hard to go by this gorgeous picture for summing it up in one:

Yes—those little specs right over on the left side are the four terrestrial planets.

It was done by Bob Riddle, and he has a bunch of related information over on his blog.

Via Brad Snowder (@skywise88).
On the topic of comparisons, did you know that the mass of Jupiter is some 2.4 times the combined mass of every other thing in our Solar System—excluding the Sun. Every planet, moon, ring, asteroid and dust mote. But even that pales next to the Sun. But wait: even the Sun pales next to the size of red super giant Betelguese, which is in our skies at present, in the Orion constellation. If Betelguese was where our Sun is, its surface would be right out past Jupiter's orbit (which is 5.2 Au, or 5.2 times the distance from Earth to the Sun, or 816,520,800 kilometres). Betelguese's radius varies between 950 and 1200 million kilometres. Now that's big...

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