Hubble Telescope May See Rare Transit of Earth in 2014

Watching the tiny silhouette of the planet Venus slowly cross the face of the sun doesn’t evoke the same drama and excitement as experiencing a total solar eclipse, but what makes a transit so unique is its rarity and historical significance.

Tomorrow's historic transit of Venus across the sun's face has astronomers and skywatchers abuzz, but how spectacular would it be to see our own planet silhouetted against the solar disk?

Venus will pass in front of the sun from Earth's perspective on Tuesday (June 5; Wednesday, June 6, in much of the Eastern Hemisphere), marking the last suchVenus transit until 2117. However, there's a chance to observe an Earth transit less than two years from now using a little creative thinking, some researchers note.

In January 2014, Jupiter will witness a transit of Earth. And we can see it too, the astronomers say, by training NASA's Hubble Space Telescope on the huge planet and studying the sunlight it reflects.

Searching for life

A transit of Earth would be an unprecedented skywatching spectacle, but the main allure of the event for scientists is the chance to see what the atmosphere of a habitable (and inhabited) world looks like from afar.

This information could help astronomers in their search for life on distant alien planets, Pasachoff said.

"We would try to detect Earth's atmosphere in that way, which would be a real analogue to finding an Earth-like planet around another star," he told SPACE.com.

Hubble is already gearing up for a similar observation of the coming Venus transit. The instrument is too sensitive to be pointed anywhere near the sun, so scientists will use the moon as a mirror. The goal is to see if Hubble can determine the makeup of Venus' atmosphere, which is well-studied, in a test of how well the technique can be applied to exoplanets.

The Hubble Space Telescope in orbit.