The true from the false. What are the bright spots sometimes visible in the sky at night?

0

Once again, trains of light spinning in the sky surprised several internet users. The phenomenon will recur in the next few days. Explanations.

“Strange phenomenon that I have just observed this evening in the sky of the Luberon. A very long train of lights (about thirty) moving at the speed of an airplane towards the East”, surprised a user on May 14 on Twitter. The next day, similar to Toronto, Canada, where a woman says she saw “to pass a line of 20-30 luminous points, in line, silent, in its sky”. On the same day, a French Internet user said he saw “passing UFOs crossing the sky from west to east. 16 perfectly aligned light points, very close to each other and more or less at equal distance”. At the risk of disappointing him, it was not UFOs but satellites.

56 Starlink satellites in orbit

It was actually 56 Starlink satellites. They were all loaded aboard the Falcon 9 launch vehicle which took off last Sunday, May 14, from Cape Canaveral, Florida. Once in the sky, the launcher dropped the fifty satellites by propelling them into space so that they put themselves in orbit around the Earth. The time to find their position, they remained close enough to the planet to be visible to the naked eye.

The devices do not emit light themselves, but at night the sun reflects off them and makes them visible, as it does with the Moon. That’s why we can see these lights that look like the lighted windows of a train that would fly away into space.

The phenomenon is quite common. Another launch took place this Friday, May 19 in the morning, which will make it possible to observe other light trains during the next few days (the Heavens Above site forecasts the times when they will be visible). There have already been two others launched in May, three in April, four in March, franceinfo already told you about it three years ago.

More than 4,000 Starlink satellites are currently in orbit around the Earth. They are part of an operation by the Space X company owned by Elon Musk, the sulphurous and much criticized owner of Tesla and Twitter, launched in 2019. Its goal is to eventually deploy 42,000 satellites 550 km around the Earth. Terre which will be networked in order to make it possible to have an Internet connection everywhere in the world, with the ambition in particular of reducing the digital divide between the rich countries and the poor countries, in particular in Africa.

Reviews from astronomers and NASA

But the American billionaire’s project is criticized for several reasons. First there is a certain vertigo in knowing that the Earth will soon be surrounded by a grid of satellites. The concern that is most heard at the moment is that of astronomers. From the start of the operation in 2019, some warned of the excessive luminosity of these satellites which, by the effect of the sun, can be confused with stars, as the magazine reported at the time. Science and Future with AFP. Elon Musk asked his teams to put an anti-reflective coating on his devices. However, this is not enough, according to an independent study by Japanese astronomers published in 2020. Too low, too close to the Earth, the satellites pass in front of their telescopes and prevent fine and long observation of the stars.

There is also a risk of pollution. According to a study published in 2021 by two Canadian researchers, these satellites represent a danger for the ozone layer and risk causing a “climate catastrophe”. According The echoesNASA also fears to see the multiplication of collisions between satellites which, broken, would then be out of service and, unable to be recovered, would remain like warts in space endangering other devices.


source site-15