December 02, 2005

Ooooooh, shiny!

The Earth from way out in space!

The big blue marble

The Earth in true-color format, as viewed from the Venus Express spacecraft. [Image: ESA/VIRTIS team]

The European Space Agency's Venus Express spacecraft is well on its way to the solar system's second planet. One of its tasks on arrival will be to make images of Venus using a photo spectrometer called VIRTIS. To make sure that VIRTIS is working correctly, mission scientists pointed it toward the Earth and Moon and made a number of test images, including the one above.

To get a sense of perspective, Venus Express was about 3.5 million km/2.75 million mi. from Earth when the image was made on November 23. If we remember correctly, that's about eight times the distance from the Earth to the Moon. While this fuzzy image isn't the kind of stunner that we've come to expect from, say, the Hubble Space Telescope, it still shows how different this blue earth is from the empty space that surrounds it.

These Earth observations will be used to test the instrument on a real planetary case, before Venus approach.

A comparison of Venus spectra with Earth spectra with the same instrument will also be of interest for textbook illustration of the comparison between the two planets, explained Pierre Drossart, the other PI.

The Moon has also been observed, providing additional observations of particular interest for calibrating the intrument.

The VIRTIS instrument on Venus Express is a twin of the same instrument on Rosetta, and similar observations were sent back by Rosetta in March 2005, so comparisons of the two sets of observations will be very useful for calibration purposes.

You can find out more about Venus Express at the project's main webpage here.

Via European Space Agency.

Posted by Magpie at December 2, 2005 03:27 AM | Shiny Things | Technorati links |