Transit of Mercury: Planet to cross in front of the sun in rare cosmic event that won't be seen for next 30 years
Mercury transits happen only about 13 times per century; The planet will visit again in 2032, though North Americans will have to wait until 2049 to witness the next one
With Mercury making a rare pass across the sun, the sky will put on a stellar show on Monday. Astronomy enthusiasts could witness this rare spectacle, which takes place once every 13 years, during the early hours of November 11.
The smallest planet in our solar system, Mercury, will move slowly across the sun, appearing as a tiny black dot against the bright sun.
“The planet Mercury is a very small, terrestrial planet, and it’s quite a bit closer to the sun than we are, so it’ll just be a tiny little black spot,” Patti Boyd, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland told NBC news.
Passing between the sun and the Earth, Mercury will take about five-and-a-half hours to complete its journey this year. Prior to the transit, NASA experts had said that watchers on the East Coast will be able to see the whole thing, but viewers almost anywhere in North America will not miss out, since Mercury will still be making its journey when the sun is up on the West Coast.
Starting its journey in the wee hours of the morning at 4.35 am PST, the transit will end at 10.04 am PST. The greatest transit time, according to NASA, will be at 7.19 am PST.
NASA had warned that looking at the sun directly or through a telescope without proper protection could lead to serious and permanent eye damage. To view such events, people were requested to use a pair of binoculars or a telescope with a certified Sun filter.
If the weather in your area played spoilsport or you lacked the right gear, you can still watch the transit through Virtual Telescope or via Slooh, which streamed the event on YouTube.
Why are these transits so rare?
Though Mercury passes between Earth and the sun approximately once every four months, enthusiasts will not be able to view this event until 2032 because Mercury's orbit and Earth’s orbit do not always align. Most often, Mercury passes above or below the sun's disk from the Earth's line of sight. And the orbits align just 13 to 14 times a century, making the Mercury transit rare.
While Mercury will visit again in 2032, North Americans will have to wait longer: they will not witness the next Mercury transit from this part of the world until 2049.
Besides Mercury, we can also view the transit of Venus, albeit even more rarely -- the last one occurred in 2012, and the next one won’t take place until 2117.