article_snippet.sent: This infographic explains how the Spitzer Space Telescope can be used in tandem with a telescope on the ground to measure the distances to planets.
article_snippet.sent: But the Spitzer Space Telescope faces one key problem: This method can't always precisely narrow down the distance to the stars and planets being observed.
article_snippet.sent: While a passing star may magnify the light of a more distant star, a passing star rarely can be seen a passing star, making the task of measuring how far away a passing star is challenging.
article_snippet.sent: That's where Spitzer can help out, thanks to Spitzer remote Earth-trailing orbit.
article_snippet.sent: When Spitzer watches a microlensing event simultaneously with a telescope on Earth, Spitzer sees the star brighten at a different time, due to the large distance between the two telescopes and the star brighten at a different time unique vantage points.
article_snippet.sent: This technique is generally referred to as parallax. '
article_snippet.sent: Spitzer is the first space telescope to make a microlens parallax measurement for a planet,' said Yee.
article_snippet.sent: Traditional parallax techniques that employ ground-based telescopes are not as effective at such great distances.'
article_snippet.sent: Ground telescopes send out alerts to the astronomy community when an event starts, but the activity can quickly fade, lasting on average about 40 days.
article_snippet.sent: Both Spitzer and Ogle's telescopes detected the telltale planetary blip in the magnification, with Spitzer seeing Spitzer 20 days earlier.
article_snippet.sent: This time delay between viewing of the event by Ogle and Spitzer was used to calculate the distance to the star and Spitzer planet.