The Perseid meteor shower.
Hello and welcome. I’m Jane Houston Jones at NASA’s Jet Propulsion Laboratory in Padadena, California.
If you’ve never seen a meteor shower, this month’s Perseids are a perfect introduction.
Plan a summer getaway on Thursday night August 12. You’ll begin to see meteors by about 11 p.m. But the rates increase closer to dawn'
The Perseid meteor shower is named after the constellation Perseus. And the meteors appear to originate near this constellation in the northeast sky.
This year’s meteor shower happens on a moonless night, so you’ll be able to see more of the fast, bright meteors.
Meteor showers are the debris of a passing comet, or sometimes the debris from a fragmented asteroid. Comets originally formed in the cold outer solar system, while most of rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.
When a comet nears the sun, its icy surface heats up. This causes clouds of gas, dirt and dust to be released, forming a tail of debris that can stretch for millions of miles. As Earth passes near this dusty tail, some of the particles hit our atmosphere. They burn up and we see the result as meteors.
NASA generates meteor shower forecasts to prevent potential hazards to spacecraft that are launching and orbiting Earth.
You’ll see some Perseids all month long, before and after midnight. But the best fireworks display will be in the wee hours of Friday morning August 13.
The European Space Agency’s comet mission Rosetta flew by asteroid Lutetia last month and returned beautiful images of this battered world.
Now Rosetta’s on its way to send a lander to a comet.
NASA’s Deep Impact EPOXI spacecraft is on an extended mission to study and search for planets orbiting distant stars. But first, in early November this year, it will fly by Comet Hartley 2.
NASA’s Stardust NExT mission will fly by Comet Tempel 1 in 2011. And the Dawn mission arrives at asteroid Vesta in 2011, and the dwarf planet Ceres in 2015.
Despite that recurring email hoax about Mars being big and bright this month, it appears as a faint, reddish object near brighter Venus and Saturn just at sunset.
Jupiter shines as a brilliant beacon nearly overhead before midnight.
Through a telescope you might be able to see nearby Uranus.
You can learn more about NASA missions at www.nasa.gov
That’s all for this month. I’m Jane Houston Jones.
 Perseid/ˋpɝsɪɪd/ 英仙座流星群之流星
 The Perseid meteor shower 英仙座流星雨
For more information about the Perseids, please visit
- http://tamweb.tam.gov.tw/forecast/2010/h10080503.htm (In Chinese)
 Perseus/ˋpɝsɪəs/ 英仙座