The world will witness a rare sighting in the sky in late February, one known as the seven-planet alignment. Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Mercury will all be visible together in the sky for just one night, BBC reported.
While such events are a matter of enthusiasm for stargazers and sky-watchers, they can also have significant impact on the Solar System.
Though all the eight major planets of the Solar System revolve around the Sun in the same flat plane, they do it at different speeds. The planet closest to the Sun is Mercury and it takes 88 days to complete one orbit, a year for the planet. At the same time, Neptune takes a staggering 60,190 days to complete one revolution around the Sun.
Occasionally, the different speeds mean that at one point several planets line up on the same side of the Sun and that is what people can see from Earth.
Now that this spectacle is coming up in February, it is notable that the seven planets might not align exactly. But, they will appear in an arc across the sky due to their orbital plane in the Solar System, the BBC report mentioned.
For the naked eye, the brighter planets like Mercury, Venus, Mars, Jupiter and Saturn would be visible. But a binocular or telescope might be needed to spot Uranus and Neptune.
Jenifer Millard, an astronomer at Fifth Star Labs in the United Kingdom, said, “There is something special about looking at the planets with your own eyes.”
“Yes, you can go on Google and get a more spectacular view of all these planets. But when you’re looking at these objects, these are photons that have travelled millions or billions of miles through space to hit your retinas,” Millard was quoted as saying.
What the alignment means
While there have been questions over the planetary alignment’s impact on solar activity, scientists’ study indicate the evidences to be weak.
Robert Cameron, a solar scientist at the Max Planck Institute for Solar System research in Germany, was cited by BCC, “The observational evidence suggests that the planets directly causing the solar cycle just doesn’t happen. There’s no evidence of any synchronisation.”
In 1977, NASA had launched a twin spacecraft, Voyager 1 and 2, to take a “grand tour” of the outer Solar System on the occasion of a similar planetary alignment of Jupiter, Saturn, Uranus and Neptune.
Voyager 1 only flew past Jupiter in 1979 and Saturn in 1980, Voyager 2 rightly used the alignment to visit all four planets, becoming the only spacecraft in history to visit Uranus and Neptune.
Notably, planetary alignments are also used by astronomers to probe the aspects of the Universe, and the discovery and study of exoplanets.
A transit method is used to find such worlds. According to BBC, in this process, a star’s light is dimmed when an exoplanet passes in front of it from human’s point of view and this allows its size and orbit to be noticed with difficulty.
This transmit method has led to the discovery of Trappist-1, a red dwarf star located about 40 light years from Earth.
Grander alignments also enable the understanding of the alignment of galaxies. The process of ‘gravitational lensing’ is one where the gravitational pull of galaxy clusters between Earth and distant early galaxies magnifies the light of the more distant one, allowing astronomers to study the far-away galaxies.
An alien civilization might also look up towards our Solar System to use such planet alignments to send communications or signals, the report mentioned.
This rare seven-planet planetary parade depends on one’s point of view, but any two planets of our Solar System can be aligned if the person is position at the right angle.
In 2024, Nick Tusay, a graduate student at US’ Pennsylvania State University, had said, “Perhaps another alien civilisation might see this as an opportunity to conduct their own investigations.”
