Gear up for the ‘planetary parade’ from June 22 to 26

Sky gazers are in for a treat because the ‘planetary parade’ or an ‘appulse, that occurs when three to six planets appear in the same part of the sky in alignment, will take place between June 22 and 26. All five of the planets visible to the naked eye—Mercury, Venus, Mars, Jupiter and Saturn—will align in an arc across the sky.

The last such event took place in 2004, and if you miss this one, you will have to wait till 2040 for another planetary parade to take place. So to catch the celestial event, wake up early and find an unobstructed view of the horizon from east-northeast to nearly due south, just before sunrise between June 22 and June 26.

The eight planets of our solar system orbit the sun in ellipses so perfectly distanced that they never come into collision, tilted in such a way that all of them are never aligned in a straight line at once. “Think of the orbits as race cars on miscalibrated tracks. They aren’t running the same race, but because of the way the tracks are placed, the planets seem to overlap because of our faraway vantage point,” said Ganesh Subramaniam, an 87-year-old space enthusiast who has been captivated by astronomy since high school. He usually finds a quiet spot near B R Hills with his telescope, away from city lights and urban pollution that ruin most people’s view of the night sky.

Read | Milky Way's secrets revealed by massive space probe map

An alignment such as this one is rare for two reasons. First, because the planets will appear in the order of their distance from the sun. Second, the earth’s satellite, the moon, marking the earth’s own position in this lineup, will also appear simultaneously in the sky. Interestingly, although difficult to spot with the naked eye, the more distant Uranus and Neptune will also be in the same section of the sky, making this a near-grand alignment of the planets, said Subramaniam.

“Although this alignment has been in the sky for a couple of weeks now, the latter half of the month is a better time to spot it as Mercury, the dimmest of the visible lot, will be higher in the sky and easier to pick out,” Subramaniam said.

Interestingly, June 21 is also the summer solstice, the day when the northern hemisphere of the earth is closest to the sun because of the tilt of its axis. This makes it the longest day of the year. The greater number of daylight hours may make it difficult for some to sleep at their usual time, but this year, with this phenomenon to look forward to, that may not be such a bad thing.