What a sight! After all these years of looking up at the Perseid meteor shower, this photo by NASA astronaut Ron Garan offers a completely new perspective. He photographed a Perseid burning up in Earth’s upper atmosphere through a window in the International Space Station and sent it to back to Earth from his Twitter account.
Judging from the clouds beneath the meteor track, few if any ground observers spotted this particular Perseid. I wonder how long he watched the shower? With never a cloud to mar the view, observing conditions must have been excellent 215 miles up. Since the station completes an orbit in about 90 minutes, if Garan sat up watching Perseids for three hours, he would have experienced two approximately 45-minute-long “nights” sandwiched between two consecutive sunrises and sunsets. Odd thought, that.
Moonlight did put a dent in Perseid meteor counts this year. On the August 13 maximum, 60-80 meteors per hour were counted by expert observers in good conditions. Sometimes that number’s 100 or more. For more details on the shower, check out the International Meteor Organization’s quicklook data page.
Amateur astronomer Terry Lovejoy of Australia has been busy photographing Comet Elenin through his 8″ (20 cm) telescope even during moonlight. When I saw his most recent image today, I thought you’d enjoy seeing it, too. It’s the first that gives you a hint that Elenin is beginning to develop a nice tail. It’s faint, but you can trace it well beyond the comet’s head.
Lovejoy is hoping for even better photos once the moon is out of the way. When a bright moon is up, a time-exposure photo records moonlight along with the stars. The extra light brightens the sky and washes out faint, low contrast details. Watch for more comet pix here soon!
A couple days ago I blogged on tomorrow’s conjunction of Venus and the sun. That’s not the only interesting planetary alignment happening this week. On the same day but later in the evening, Mercury will also be in conjunction with the sun. However, instead of behind the sun – as Venus will be – Mercury will be in in front of the sun. Venus’s conjunction is called ‘superior’ because it’s on far side of the sun from Earth; Mercury’s is ‘inferior’, because it’s on the near side.
This match-up on the same day is a relatively rare event, but don’t expect it to cause any measurable effects on Earth – the planets are simply too far away. Nor will we see Mercury and Venus with the unaided eye. They’re too close to the sun and lost in its glare. With no atmosphere to scatter light and create a bright blue sky, the moon would be a good place to view the threesome, so long as you blocked the sun with your gloved finger. This best viewing option might be the coronagraph on NASA’s Solar and Heliospheric Observatory. It’s currently showing a great view of Venus and the sun, but the field of view is a bit too small to include Mercury. Check out a recent image.
Planet lineups are quite common during any given year. In 2011, there are 22 conjunctions (lineups) among the seven planets and dwarf planet Pluto. Mercury alone lines up with Earth and the sun at inferior and superior conjunction six times this year. Since the planet orbits the sun every 88 days, that should come as no surprise.
Any gravitational effects from these planetary fun-and-games are tiny compared to the much closer moon and sun. Many are very enjoyable to watch, since we humans get a thrill seeing two bright celestial bodies near one another in the sky. The next cool pairing, or should I say ‘gathering’, happens in late October through mid-November, when Venus, Mercury and Saturn play tag in evening twilight.