Mercury Makes Rare Move Across The Sun

BALTIMORE (WJZ)—NASA turned its instruments to the planet Mercury today, as it crossed between the Earth and the Sun.

Alex DeMetrick reports, Mercury's transit might help find other worlds around other starts.

Mercury is the planet closest to the sun, and today it showed just how close, as it passed directly between the Sun and the Earth.

Known as a transit, it only happens 13 times a century, and NASA carried it live.

The transit also gave spacecraft observing the sun, a sharp target to focus in on.

"It allows us to calculate and fine tune the cameras and give us even better resolution," said Dr. Alex Young, with NASA's Goddard Space Flight Center.

The better the imagery, the better science understands the threats from massive solar eruptions.

But that little black spot on the Sun today, actually dims the brightness by a tiny amount.

"We see a very small, very precise dip and we're looking for these exact dips around other stars when we look for transiting exoplanets," said Dr. Padi Boyd, who also works at the Goddard Space Flight Center.

Those exoplanets have been found around distant stars.

Next year NASA will be looking for transits at nearby stars, and before the end of the decade, the James Webb Space Telescope will look to the most promising, with one hundred times the power of the Hubble Space telescope.

"And put all that information together to tease out the spectrum of the planet and its atmosphere," said Padi

It's like following stepping stones in the hunt for a critical ingredient.

"We may see water on planets going around other stars. That's the first place to look if you're going to find life," said Dr. Matt Mountain, Assoc. of Universities for Research in Astronomy. "Ultimately, we're going to have to find another home for the human race."

Mercury's transit took over seven hours. It won't happen again until November 2019.