Skylights featured on Astronomy Picture of the Day

Scout Report Selection Webivore Selection SpaceCareers Selection

Skylights featured nine times on Earth Science Picture of the Day: 1 2 3 4 5 6 7 8 9


Photo of the Week. Spectacular sunburst.

Astronomy news for the week starting Friday, February 26, 2010.

Our perpetual Moon, which has rounded the Earth for some 4.5 billion years, passes through yet another full phase this week, on Sunday, February 28, during daylight in North America. It will thus rise just short of full the evening of Saturday the 27th, and just a bit beyond that phase the following night. So we get to see a couple days of the waxing gibbous, and then a long run the rest of the week of the waning gibbous phase, third quarter not achieved until Sunday the 7th.

The nights of Friday the 26th and Saturday the 27th find the Moon passing south of the Sickle of Leo, while the night of Monday, March 1 (more the morning of Tuesday the 2nd), look for the Moon to be eight or so degrees south of Saturn . A day before full, the Moon passes perigee, where it is closest to Earth. Watch out for high tides. Though not in the midwest.

It's time to celebrate Jupiter, though by its absence, as it finally passes conjunction with the Sun at the end of our short month, on Sunday the 28th. The giant planet, which is not so much a gas giant but a ball of liquid molecular hydrogen, will thereafter appear in the morning sky, though it will not be visible in twilight until April warms the ground.

As for large planets, then, Saturn will have to serve. And it and its ring system do so beautifully, the planet now rising just after the end of evening twilight, still in Virgo just 3.5 degrees east of the Autumnal Equinox (and in retrograde, slowly closing in on it). Retrograde, westerly, planetary motion was of course the original clue that the planets go around the Sun (rather than Earth), as this backward motion occurs as we pass them (or they pass us) in orbit. Saturn then crosses the meridian to the south around 1:30 AM and is still in the sky, to the east, at dawn.

But never mind so much Saturn, about keep your eye out for Venus , which now rises in mid-twilight, and thanks to a high tilt of the ecliptic is becoming ever more visible. Once seen, it will be with us most of the year, not crashing through twilight again until September, creating for us a glorious summer sight.

That leaves Mars. Though still bright, it is noticeably fading as it transits the meridian ever earlier, now around 9:30 PM, the planet setting about as twilight lights the morning sky. It's in a fine setting between Gemini's Castor and Pollux pair and Cancer's Beehive Cluster.

If there is a season for Sirius, the luminary of Canis Major (the Larger Dog), this is it. At least in early evenings, when the star shines brightly to the south. One of the closest stars to Earth, only 8.6 light years away, it is famed for its twinkling sparkle, the result of variable refraction and dispersion in the Earth's atmosphere. It's even better known for its companion, a shrunken white dwarf about the size of Earth that was at one time by far the more magnificent of the two.
Valid HTML 4.0!