Skywatchers in the United States will be able to watch Mercury pass between Earth and the Sun on Monday, May 9, according to the National Aeronautics and Space Administration (NASA). The smallest of the eight planets in the Solar System will become visible as a tiny black dot. Events of this kind occur only thirteen times a century.

Two NASA satellites will transmit images of the transit while a third will offer an almost-live feed. Mercury is expected to pass between our planet and the sun, from 7:12 a.m. to 2:42 p.m Eastern Daylight Time, according to a NASA’s statement issued Wednesday.

Skywatchers in the United States will be able to watch Mercury pass between Earth and the Sun on Monday, May 9. Photo credit: Nemesis Maturity
Skywatchers in the United States will be able to watch Mercury pass between Earth and the Sun on Monday, May 9. Photo credit: Nemesis Maturity

Mercury gets close to the sun every 88 days. However, the Earth, the sun, and the small planet do not commonly align. Transits are a major opportunity for astronomers, to analyze how planets and stars move in space, said NASA.

For instance, information obtained from the planet’s movement can help scientists, to calibrate their instruments. Just for that reason, the space agency will dedicate three solar telescopes to watch the transit. Mercury cannot be seen without optical augmentation, however, people can use a telescope or binoculars with proper solar filters.

“Astronomers get excited when any two things come close to each other in the heavens. This is a big deal for us. Back in 1631, astronomers were only doing visual observations on very small telescopes by today’s standards.” said Louis Mayo, program manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a press release.

The first time astronomers observed a Mercury transit, was in 1631. Since that time, scientists were able to measure the alleged size of Mercury’s disk. They also calculated the possible distance from Earth to the sun, added the NASA. Currently, space agencies use data of transits to test spacecrafts and instruments.

Many space agencies will jointly work to analyze the Mercury transit

The May 9 transit will be observed by scientists for the Solar and Heliospheric Observatory (SOHO), a spacecraft managed by NASA and the European Space Agency. Hinode, a collaboration between space agencies of Japan, the U.S., the U.K., and Europe, will also analyze the event, under the command of the Japan Aerospace Exploration Agency.

Decades ago, it was hard to observe transits, said SOHO Project Scientist Joseph Gurman. However, instruments in the spacecraft can help scientists with the task, even when Earth conditions such as bad weather are interfering. The analysis of the Mercury transit will also help astronomers determine the solar rotation axis.

Source: NASA Press Release