Don't miss this month's rare planetary alignment
Step outside this week into the chilly predawn. You may see the planet Mercury peak over the horizon. Then trace an arc across the sky. You may pick out Venus, Saturn, Mars and Jupiter. All five will be visible together. This will happen for the first time since 2005.
The latter four planets have been shining in the early morning since the beginning of the year. So writes Tanya Hill for The Conversation. "It is the appearance of Mercury that makes the family complete," she adds. You can take in the show. But it depends on your location.
Mercury usually hangs close to the horizon. It is the most difficult to see. But it will slowly cross higher in the sky. By early February, it will be easier to spot.
The waning moon will travel along the line of planets starting January 28. It will start out at Jupiter. And it will rest near Mercury by February 7. Venus and Saturn will dance in particularly close conjunction on February 9. This is according to Bruce McClure and Deborah Byrd for EarthSky.org.
Each planet orbits at different distances from the Sun. So each planet takes different periods of time to complete a year. This kind of alignment in the Earth's sky is rare. The fact that they do stack up in a line is visual proof that the planets do orbit on roughly the same plane, Hill writes.
"There are only a few amazing things in the night sky that can be seen without any equipment," notes Alan Duffy. He is a research fellow at Swinburne University in Melbourne. He spoke with Anne Johnson of Australian Geographic. The planetary alignment is one of those things that can be seen.
It is worth an early rise. Duffy does offer a warning. He says some people may have to travel farther than their front stoop to get an open view of the horizon. Trees, buildings and city lights can all block the rare views.
So make sure you prepare for the show. And figure out when Mercury will rise near you. To find out, use the United States Naval Observatory's webpage. Hope for clear skies and bundle up. This may be the best view of the five planets aligned for quite a while. According to EarthSky.org, the group will gather again in August. But only those in the Southern Hemisphere will really get to see the next show.
CRITICAL THINKING QUESTION
Why is no telescope needed to see these planets?
Write your answers in the comments section below