The above image of Messier 78, a reflection nebula in Orion (but not the Orion Nebula), overlays observations from the ESO’s Atacama Pathfinder Experiment (APEX) telescope on top of Digital Sky Survey imagery. APEX records in the millimetre and sub-millimetre wavelengths — essentially it’s a microwave telescope — and reveals (in orange) cold, dark dust clouds that would otherwise be hidden. Image credit: ESO/APEX (MPIfR/ESO/OSO)/T. Stanke et al./Igor Chekalin/Digitized Sky Survey 2.

Other recent awesome space pictures include the Chandra X-ray Observatory’s discovery of a black hole outburst in M83, the Herschel Space Observatory’s infrared view of the Cygnus X star-forming region and the ESO’s infrared look at globular cluster M55. The Isaac Newton Group of Telescopes released this narrowband image of the Thor’s Helmet nebula. And last but not least, Jason Major’s colour composite of Titan and Saturn, based on new Cassini images.

Just look at this Hubble image of the Egg Nebula, a protoplanetary nebula on its way to becoming a planetary nebula: in particular, note the searchlight beams emanating from the dying central star, itself hidden by a surrounding dust cloud. Wow. Image credit: ESA/Hubble, NASA.

Other recent awesome space pictures include MESSENGER’s look at Mercury’s Donne crater; the ESO’s wide-field view of star cluster NGC 6604; and two infrared views of Messier 104, the Sombrero Galaxy, from the Spitzer Space Telescope that reveal that its well-known disk is actually enveloped by an elliptical galaxy structure: one, two.

If last week’s look at the Tarantula Nebula wasn’t enough for you, and I suspect it might not have been, then your dissatisfaction may be cured by this composite image assembled from three different orbiting telescopes. It shows the exact same view as last time, only this time visible-light observations from the Hubble (now coloured green) have been combined with infrared data from the Spitzer Space Telescope (here coloured red) and X-ray data from the Chandra X-Ray Observatory (here coloured blue). Image credit: NASA/JPL/PSU/L. Townsley et al. (infrared); NASA/STScI (optical); NASA/CXC/PSU/L. Townsley et al. (X-ray).

What’s that you say? Another Hubble image of 30 Doradus, the Tarantula Nebula? I don’t know, I’ve posted an awful lot of images of that nebula before … oh, what the hell. The Tarantula Nebula is awesome. It’s 160,000 to 180,000 light years away in the Large Magellanic Cloud. It’s huge: this image is 650 light years across. It’s so bright that if it were as close to us as the Orion Nebula (a relatively puny star-forming region, but the closest to us at 1,500 light years), it would cast shadows. And I can’t see it through my telescopes because I’m in the wrong hemisphere. Bummer.

This image is a mosaic assembled from infrared observations by the Hubble and ground-based observations of the hydrogen-alpha oxygen-III emission wavelengths by the 2.2-metre MPG/ESO 2.2-metre telescope at the ESO’s La Silla site. It was released to celebrate the Hubble’s 22nd anniversary.

Image credit: NASA, ESA, ESO, D. Lennon and E. Sabbi (ESA/STScI), J. Anderson, S. E. de Mink, R. van der Marel, T. Sohn, and N. Walborn (STScI), N. Bastian (Excellence Cluster, Munich), L. Bedin (INAF, Padua), E. Bressert (ESO), P. Crowther (Sheffield), A. de Koter (Amsterdam), C. Evans (UKATC/STFC, Edinburgh), A. Herrero (IAC, Tenerife), N. Langer (AifA, Bonn), I. Platais (JHU) and H. Sana (Amsterdam).

A coronal mass ejection is under way on the Sun right now, and NASA has posted ultraviolet-wavelength image and movies of the event from the Solar Dynamics Observatory. The solar flare with which this is associated is only considered medium-sized. Boggle. Image credit: NASA/GSFC/SDO.

Calling it “the first entirely new globe of the lunar surface in more than 40 years,” Sky and Telescope has announced a new Moon globe based on Lunar Reconnaissance Orbiter imagery. Replogle’s Moon globe has been the standard for decades, but it’s based on 1960s-era charts and, as I said in my review three years ago, doesn’t have a lot of contrast and doesn’t look much like the Moon. Mind you, the new globe costs almost twice as much.

This Hubble image of globular cluster Messier 9 was released earlier this month. The image shows both visual and infrared light (red represents the near-infrared). Messier 9 is about 26,000 light years away in the constellation Ophiuchus. Via Universe Today. Image credit: NASA and ESA.

The search for exoplanets — that is, planets orbiting other stars — is essentially an exercise in statistical sampling. The Kepler mission, for example, looks at more than 145,000 stars over several years to see if a planet transits them; the percentage of stars found to have planets, or more than one planet, or a planet in its habitable zone, can be extrapolated to the entire galaxy, giving us a rough (and invariably mind-boggling) number of just how many worlds are out there.

The European Southern Observatory has done something similar, though from closer to home and at a smaller scale. Their six-year spectrographic survey of 102 red dwarfs found a total of nine super-Earths, including two within the stars’ habitable zones. The implication of this discovery becomes clear when the sheer number of red dwarfs is taken into account: there are tens of billions of rocky planets out there. Not only that: “As there are many red dwarf stars close to the Sun the new estimate means that there are probably about one hundred super-Earth planets in the habitable zones around stars in the neighbourhood of the Sun at distances less than about 30 light-years.” That’s of more than just statistical interest.

(Whether planets around red dwarfs are in fact habitable is a subject of some debate, since red dwarfs are prone to rather lethal flares, and their habitable zones are so close that the planet would be tidally locked, with one side always facing the star and the other side terribly cold.)

Previously: First Habitable-Zone Planet Confirmed.

Here’s a pretty ultraviolet image of the Cygnus Loop nebula, a supernova remnant a mere 1,500 or so light years away, taken by the GALEX ultraviolet space telescope. Amateur astronomers will be more familiar with those parts of the Cygnus Loop that appear in the visible part of the spectrum: the Veil Nebula. Image credit: NASA/JPL-Caltech.

In my review of Paul Schenk’s Atlas of the Galilean Satellites I noted that the maps of Jupiter’s four largest moons were actually spacecraft imagery placed on a map projection; there were no non-photographic maps. In that context, the geologic map of Io, just out from the U.S. Geological Survey, is both novel and pertinent. The maps are based on Voyager- and Galileo-derived photomosaics of Io’s surface released in 2006, but they’re maps. ASU news release, Universe Today.

Paul Schenk’s Atlas of the Galilean Satellites (Cambridge University Press, 2010) collects all the imagery gathered by the Voyager and Galileo missions of the four major moons of Jupiter (Callisto, Ganymede, Europa and Io, all discovered by Galileo in 1610) and assembles them into global, quadrangle and area maps. But this heavy, 400-page tome begins with a confession. “This Atlas is not what it should be.” The failure of the high-gain antenna on the Galileo spacecraft meant that far less data could be transmitted back to Earth during its nearly eight-year mission than had been planned. Large tracts of the moons are mapped in low resolution; the fuzzy images yield little detail. But until another mission is sent — the Juno probe now en route to Jupiter will not be studying the moons — this is all there will be for the foreseeable future. For decades, in fact.

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Saturn’s moon Iapetus is bizarre for many reasons, one of which is its 13-kilometre-high ridge along its equator (which makes Iapetus look rather like a walnut). A scientific paper now in press has a theory as to how it happened, which Emily Lakdawalla explains in detail: Iapetus may once have had its own moon (or submoon), which was drawn too close, torn apart, and formed into a ring. The ring particles de-orbited gently over time, building up the ridge. Image credit: NASA/JPL/Space Science Institute.

Chinese scientists have released a high-resolution map of the Moon based on images from the Chang’e 2 spacecraft; the maps are at a resolution of seven metres (MoonViews, Universe Today). Phil Stooke compares the Chang’e 2 images with those from the Lunar Reconnaissance Orbiter Camera (LROC). Meanwhile, and speaking of the LROC, Jeffrey Ambroziak is making 3D anaglyph maps based on LROC data; he’s launched a Kickstarter campaign to create a 3D digital map of the entire Moon.

Mercury’s unusual Hovnatanian crater, the result of an oblique impact, as captured last month by the MESSENGER probe. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Other pretty space pictures this week: a Hubble image of the centre of globular cluster NGC 6752; and an ESO image capturing the magnificent Carina Nebula in infrared.

Oh look, another nebula picture from the European Southern Observatory. Again? Yes. I make no apologies, people. This little beauty is NGC 3324, a stellar nursery some 7,500 light years away in the southern constellation Carina. This pretty picture comprises light through visual, oxygen-III and hydrogen-alpha filters captured by the MPG/ESO 2.2-metre telescope at La Silla. Nancy Atkinson thinks it looks like Alfred Hitchcock. Image credit: ESO.

Other pretty space pictures I spotted this week: barred spiral galaxy NGC 1073, courtesy of the Hubble; and, closer to home, Saturn’s moon Dione in front of an edge-on look at the rings, courtesy of Cassini.

If, like me, you often wonder how far out radio signals can be detected before they’re drowned out by cosmic background radiation — for example, you’re working on a science fiction story that depends on being able to detect such signals from other stars — then, like me, you’ll be interested in this Ask MetaFilter thread and the SETI range calculator. Short version: broadcast radio signals fade out pretty fast thanks to the inverse square law, so it’s pretty unlikely that space aliens will be along to demand explanations for our 1950s television programs.

Infrared astronomy is the bomb. Here’s an infrared look at the Helix Nebula, a planetary nebula some 700 light-years away — which is to say, not all that far as these things go — in the constellation Aquarius. This was taken by the VISTA telescope at the ESO’s Paranal Observatory in Chile. Compare with how it looks in visible light: infrared brings out all kinds of interesting structure. Image credit: ESO/VISTA/J. Emerson; acknowledgment: Cambridge Astronomical Survey Unit.

This stunning view of Messier 16, the Eagle Nebula, is a composite image that combines far-infrared wavelengths captured by the Herschel Space Observatory and X-rays from the XMM-Newton space observatory. Obviously this is a false-colour image: these wavelengths are invisible to the human eye. For a visible-light view of the nebula, see this image from the ESO’s La Silla observatory — though it’s just a grey smudge if you look at it through a small telescope. The Eagle Nebula was also the location of the famous Hubble “Pillars of Creation” photo (also a false-colour image showing chemical emissions), and you can sort of see it in the above image as well. Image credit: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium (infrared); ESA/XMM-Newton/EPIC/XMM-Newton-SOC/Boulanger (X-ray).

The ESA’s Hubble website released this detailed view of the centre of Messier 82, a starburst galaxy 12 million light-years away in the constellation Ursa Major. M82 is a very well-known galaxy: I’ve seen it myself through the telescope; it makes a pretty pair with the nearby spiral galaxy Messier 81, interactions with which are triggering the outbreak star formation that is characteristic of a starburst galaxy. This is a view of M82’s core, through hydrogen-beta, sulphur-II and oxygen-III emission filters and in the ultraviolet. See also this Hubble wide-field view from 2006 and this composite view in the visual, infrared and X-ray bands. Image credit: ESA/Hubble and NASA.

Sungrazing comet C/2011 W3 Lovejoy passed through the Sun’s corona and survived. It is now providing a spectacular sight to viewers in the southern hemisphere and on the International Space Station. Above, a time-lapse video of Comet Lovejoy rising above the Andes, by Stéphane Guisard (via Bad Astronomy). It looks huge; I’m very sorry this can’t be seen from the northern hemisphere.

For some reason, it’s the time of year when too many goddamn awesome space pictures get posted. Here are a few of the DSO variety. Above, a newly released Hubble image of Sharpless 2-106, a star-forming region 2,000 light years away. Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).

Elsewhere in our galaxy, amateur astrophotographer Rogelio Bernal Andreo takes the most amazing wide-field astrophotos: don’t miss this stunning image of supernova remnant Sharpless 2-240. Puppis A is another supernova remnant; WISE imaged it in infrared. Another gem from the Sharpless catalogue, 2-239, made APOD on December 8.

Much further afield — 480 million light years, to be more or less exact — the Chandra X-ray telescope imaged gas “sloshing” around galaxy cluster Abell 2052; Phil Plait explains the enormous scale involved. Finally, closer to home, Tycho’s Supernova shines in gamma rays.

The Cassini spacecraft performed its closest-ever flyby of Saturn’s moon Dione yesterday. In the above image, taken from a distance of 112,636 km from Dione, the moons Epimetheus and Pandora, as well as Saturn’s rings, can also be seen. This image was taken from a distance of 77,682 km. And this image reveals Saturn’s moon Mimas poking out from behind the dark side of Dione. Image credit: NASA/JPL/Space Science Institute; I added some sharpening and highlight correction.

An oblique, high-resolution view of Mercury’s Bartok crater, about 117 km across, courtesy of the MESSENGER probe. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

One full rotation of big scary Jupiter, observed over a week in October by the one-metre telescope at the Pic du Midi observatory. Via APOD. Credit: S2P IMCCE/OPM/J.-L. Dauvergne/Elie Rousset/Eric Meza/Philippe Tosi/François Colas/Jean Pajus/Xavi Nogués/Emil Kraaikamp.

Kepler-22b, the first planet outside our solar system confirmed to be within its star’s habitable zone by the Kepler spacecraft, orbits a G-type star 600 light years away, and has a day 290 Earth days long (we’ll probably never learn how long its own day is). That doesn’t sound too different from our own planet, but at 2.4 times Earth’s radius it’s substantially larger, which is to say it’s a super-Earth. Questions probably never to be answered: whether it has a breathable atmosphere or liquid water, whether it’s rocky, watery, metallic or gaseous, or whether it’s inhabited. It’s out there: that’s about it. Image credit: NASA/Ames/JPL-Caltech (artist’s conception).

This image of Mercury is a mosaic assembled from thousands of MESSENGER images (with the missing gaps filled in by older imagery from Mariner 10) and made into an orthographic projection showing half the planet. Caloris Basin can be seen prominently in the northern hemisphere. Like the Mars mosaic I linked to last March, this is more like a globe than an actual photo. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Via Emily Lakdawalla.

Here’s an infrared look at the Cygnus X star-forming region, 4,500 light years away, home to a number of OB associations — loose groups of hot, short-lived stars. More from the mission page of NASA’s Fermi gamma-ray telescope (though this is, as I said, an infrared image — 8 µm, to be exact). Image credit: NASA/IPAC/MSX.

A new topographic map of the Moon from the Lunar Reconnaissance Orbiter: “Today the LROC team releases Version 1 of the Wide Angle Camera (WAC) topographic map of the Moon. This amazing map shows you the ups and downs over nearly the entire Moon, at a scale of 100 meters across the surface, and 20 meters or better vertically.” Late last year lunar topo maps were released that were based on laser altimeter data; presumably the WAC data, based on stereo observations, is better. Image credit: NASA/GSFC/DLR/Arizona State University.

If you hang around the astronomy-obsessed corners of the Interwebs like I do, you’ve probably already seen this five-minute time-lapse video compiled from footage taken by astronauts on the International Space Station. Gape at the pretty aurorae, watch the flickr of the thunderstorms, try to figure out where you are from the pattern of the city lights — one way or another, you’ll be impressed. Via Bad Astronomy.

Previously: An Aurora from Orbit.

A friend of mine asked whether asteroid 2005 YU₅₅, which will pass between the Earth and the Moon tomorrow, will be visible to the naked eye, since it’s bigger than the International Space Station (which we can see passing overhead).

The short answer is no. At 400 metres in diameter, 2005 YU₅₅ is bigger than the ISS, which is 109 metres wide along its truss. But the space station is a lot closer: it orbits at an altitude of between 376 and 398 kilometres. 2005 YU₅₅, on the other hand, will pass by at a distance of around 325,000 kilometres — more than 800 times further away.

There are additional complications. 2005 YU₅₅ is a C-type asteroid made of carbonaceous materials and is as such very dark. Universe Today’s Jason Major says that it’s “effectively darker than coal, reflecting less than 1% of the sunlight that it receives.” And we’re approaching full moon, which will wash out dimmer objects in the sky. Observing guides suggest that a telescope with at least six inches of aperture will be required to see it (Astroguyz, Space.com). That’s not to say that there aren’t plans to observe it or image it, but Hale-Bopp this ain’t. You’ll need equipment.