Skytalk

Let’s sing the praises of NASA superstar Peggy Whitson! Now back on Planet Earth after 288 days in space, she’s now the most experienced U.S. astronaut with 665 days on orbit. That’s 131 days more than her nearest competitor, Jeff Williams. Whitson has also logged 60 hours and 21 minutes of cumulative spacewalk time!

NASA’s Cassini is on its final orbit now, heading to destruction on Friday morning. It is expected to fragment under impact stress while still transmitting data about the interior of Saturn as it goes.

Voyager 1 left Earth 40 years ago, on September 5th, 1977. Voyager 2 left first, on August 20th. Amazingly, both are still functioning. They are getting ever closer to the edge of the solar system.

Asteroid Florence will pass Earth on Saturday. At 2.4 miles in diameter, it’s the largest since researchers began keeping close tabs on near-earth asteroids. The asteroid will pass us by at 18 times the distance from Earth to the moon – not close at all!

We’ve now lost 25 minutes off sunsets and 30 minutes off sunrises – that’s an hour daylight change already from the solstice.

Monday’s lunar eclipse is the precursor to the August 21 total solar eclipse that will traverse the United States. Dr. Pitts and Dave Heller discuss celestial mechanics and proper eclipse-viewing safety. Saturday is the peak of the Perseid Meteor Shower, making this a great week for astronomy!

We are now just three weeks out from a total solar eclipse traversing the United States. Those lucky enough to be in the direct path will experience totality for some 2-and-a-half minutes. NASA will stretch that totality to over eight minutes by flying a retired bomber aircraft to chase the solar eclipse Monday 8/21. Their intent is to study the corona in Hi-Res Infra Red and Visible light to try to understand why, if the corona is so hot (millions of degrees), it is so uniform and organized. NASA will also will look for asteroids near the sun and Mercury.

Brown University scientists have identified additional water signatures on the moon. Indication from analysis of surface lava flows suggests that the mantle of the moon contains larger amounts of water than previously expected. There are potential implications for use of the moon as a forward base of exploration of the solar system.

This is a great week to watch the development of lunar phases. Start watching on Monday night, with a barely visible 1.5-day old thin crescent that sets about an hour after the sun; you should see it near the western horizon at 8:30 P.M. On Monday and Tuesday night, you’ll have a great display of “Earthshine.”

New Horizons is on a billion-mile cruise to MU69, a Kuiper Belt Object that’s been selected as the next object the satellite will fly by in 2019. The spacecraft left Earth in January 2006 at 36,000 mph – that’s 100 times faster than a jetliner.

The smallest star ever just found, called ELBM-J0555-57Ab, is just about the size of Saturn but 300 times as massive. That makes it just 8% of the sun’s mass, yet it’s just big enough to actually BE a star according to thermonuclear fusion principles.

48 years ago this week, Neil Armstrong and Buzz Aldrin walked on the moon. They spent 21 hours on the moon and were outside just 2.5 hours.

The Juno spacecraft orbiting Jupiter flew over the Great Red Spot last week. Just 2,200 miles above the cloudtops, the photos released last Friday show amazing detail. Scientists hopefully will learn more about the great storm and Jupiter’s inner atmosphere.

A thin crescent moon joins Venus in the pre-dawn sky on Thursday. From 4:40 a.m. to 4:50 a.m. you’ll also see ISS fly from NNW to E and it goes right under Venus and the moon!

On this date in July 1997, NASA placed the first rover on Mars. Sojourner was followed by Spirit and Opportunity, then Curiosity. It was preceded by Vikings I and II. All lasted far longer than expected.