This week, if you have the chance to get up early and look east into the predawn sky, you could easily spot four of our solar system’s planets in an almost perfectly straight line. Jupiter, Venus, Mars and Saturn appear in a row from the lower left part to the right, upper part of the sky, with Venus the brightest of all.
In ancient China, if a royal astronomer saw four bright planets lining up closely in the sky, he would scramble to report to the emperor that warnings had been sent from above.
“When four planets come together, a virtuous emperor will lead his country to prosper but an immoral emperor will be destroyed,” stated Jinzhou Astrology, a classic book purportedly compiled during the Han dynasty but later lost.
Such an astronomical phenomenon, special as it might seem, was neither unfavourable nor very rare, said Zhu Jin, an astronomer and former curator of Beijing Planetarium. Since all planets revolve around the sun in the same virtual plane, seeing them in a line simply meant they were on the same side of the sun from Earth’s vantage point, he said.
As Jupiter and Venus keep drawing closer over the week, they will appear extremely close – almost kissing each other – on Sunday between 4am and sunrise.
The phenomenon, called the Venus-Jupiter conjunction, happens about once a year, but this time viewers in China will be especially well-positioned to view it, he said.
Both planets will be very bright, with Venus appearing brighter on the lower right of the pair. The two will remain very close to each other for two days before appearing to head in separate directions.
About two months from now, there will be a once-in-a-few-decades event when all the major planets in our solar system except Earth create a more spectacular line, stretching out over a larger section of the sky.
You will probably be able to see Mercury, Jupiter, Venus, Mars and Saturn with the naked eye, but need a telescope to find Neptune and Uranus.
The eight major planets could never come into actual alignment, for instance from above the ecliptic plane, because of their orientation and orbit tilt, Zhu said. The last time the eight planets appeared in the same part of the sky was over 1,000 years ago, and it will not happen again for about another 500 years.