Jane Houston Jones: What's Up for March. Watch starlight get blocked by a passing asteroid, planets march across the sky and a lunar eclipse preview.
Hello and welcome. I'm Jane Houston Jones from NASA's Jet Propulsion Laboratory in Pasadena, California.
This month, on March 20th at 2:06 a.m. Eastern time, some lucky viewers in northeast America and Canada can watch Leo's brightest star Regulus disappear for up to 14 seconds as asteroid 163 Erigone passes in front of it. This passage of one celestial object in front of another is called an occultation. The most familiar occultation is a total solar eclipse, when our moon passes in front of, or occults, the sun. Another common occultation is when the moon passes in front of a planet, like this occultation of Venus during the daytime in August 2012. The ground track for the occultation of Regulus is a 67-mile-wide path from the North Atlantic to the New York metropolitan area on to Ontario and the Arctic. If you live somewhere along the ground track, set your alarm and step outside before 2 a.m. on March 20th to familiarize yourself with the constellation Leo. It's easy to spot in the southwest sky between Jupiter and Mars, with the moon and Saturn nearby, too. The backwards question mark which outlines Leo's mane is easy to find. Regulus is the dot below the question mark.
Regulus is the dot below the question mark. Asteroid occultations are quite common, but most are so faint you need a telescope and a timepiece to follow the action.
Dedicated and patient amateur astronomers record a star's appearance and disappearance from different locations. These observations are compiled to reveal the silhouette of the asteroid. If you aren't in the ground track, check out Leo anyway and take a look at brilliant, blue-white Regulus. An occultation of a bright magnitude 1 star like Regulus won't happen again until December 2023.
There's a lunar eclipse next month, so mark April 15 on your calendar.
Until then, you can't miss Jupiter high overhead in the evening sky. And Mars and Saturn glide through the sky from midnight to dawn. Early risers can spot Venus and Mercury in the southeast before dawn.
You can learn about all of NASA's missions at www.nasa.gov.
That's all for this month. I'm Jane Houston Jones.
Page Editor: Tony Greicius