Mick Hartley

At the Atlantic they're running their traditional Hubble Space Telescope Advent Calendar. Here are a couple that've caught my eye so far:

[NASA and The Hubble Heritage Team, STScI / AURA]

The Sombrero galaxy, Messier 104 (M104). The galaxy's hallmark is a brilliant white, bulbous core encircled by the thick dust lanes comprising the spiral structure of the galaxy. As seen from Earth, the galaxy is tilted nearly edge-on. We view it from just six degrees north of its equatorial plane. At a relatively bright magnitude of +8, M104 is just beyond the limit of naked-eye visibility and is easily seen through small telescopes. The Sombrero lies at the southern edge of the rich Virgo cluster of galaxies and is one of the most massive objects in that group, equivalent to 800 billion suns. The galaxy is 50,000 light-years across and is located 28 million light-years from Earth.

How can an object with a clear shape like that be 50,000 light years across?? Well yes, no doubt it's exploding out, but still….

Closer to home:

[J. Spencer (Lowell Observatory) and NASA / ESA]

Io over Jupiter. Jupiter's moon Io, roughly the size of Earth's moon, appears to be skimming Jupiter's cloud tops, but it's actually 310, 000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas our moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut.

For UK readers, a Connecticut is 0.69 of a Wales.