Not only that, but the green planet’s gravity will likely cause its orbit to be drastically altered, to the point of turning it into a temporary Earth’s Moon!
However, there is one fact that everyone is surprised: this object is almost certainly not a meteorite. Instead, astronomers claim it is actually an auxiliary propulsion of the rocket from the 1966 lunar mission.
This object, called 2020 SO, was discovered in September 2020 by the Pan-STARRS telescope, a special glass used to search the sky, searching for objects near Earth. Not long after the object was discovered, astronomers suddenly noticed that its orbit seemed erratic: exactly the same. Its size, shape, and geometrical structure are suspiciously close to Earth’s orbit.
That’s an odd thing for a meteorite, but it’s not uncommon if you’ve ever seen the trajectory of an auxiliary rocket or space satellite. Therefore, astronomers reverse-traced its orbit and made an interesting discovery: in September 1966, it was very close to Earth! If it had been a meteorite, it would have been flying past us since then, but if it was actually the product of a space mission, September 1966 would have been the launch date.
And as expected, a spaceship was launched that day, its name was Surveyor 2, a mission designed to send a probe to the Moon.
In fact, things are more interesting than that. Surveyor 2 was launched on September 20, 1966 by the Atlas-Centaur missile. The first floor Atlas worked well, and the upper Centaur later pushed the spacecraft towards the Moon. However, an edit made mid-mission by Surveyor 2 was unsatisfactory, leaving the spacecraft off course and unable to recover any more. A few days later, it crashed into the Moon at a speed of nearly 10,000km / h.
But the second floor of the missile – the Centaur booster – continued to fly. It crosses the Moon and goes into orbit around the Sun.
The upper Centaur, like the one used to propel the Surveyor 2 – 2020 SO spacecraft, is most likely like this.
Is 2020 SO the other Centaur missile?
The likelihood is high. The brightness of 2020 SO shows that it is 4-10m across. Centaur size 3x13m, quite suitable.
And there is another reason to think they are the same. Careful measurements of the foreign object’s orbit indicate that it is strongly influenced by pressure from sunlight. Photons from the Sun touch the object and are reflected back, gradually changing its momentum. This force (similar to the YORP effect) slowly changes the trajectory of an object, but for smaller objects the change is much more noticeable. A used rocket auxiliary propulsion is a large, hollow tube, so this effect will be quite strong … just like what astronomers have discovered.
Since 2020 SO’s orbit is very similar to Earth, when one catches up to the other, the process is relatively slow (like two cars on a highway: they may be moving fast, but from inside one vehicle, you will see the other slowly passing by). In November 2020, it entered what is known as Earth’s “Hill Book”, which is the space around Earth where our planet’s gravity is stronger than the Sun. This section has a radius of about 1.5 million km.
Normally, an alien object will pass through this part easily, but 2020 SO moves quite slowly, enough to be caught by the Earth in just a short time. It will take about 4 months for it to make a large single circle around us, then the second time it passes the gravity of the Moon, Earth will give it enough energy to escape again, and once again becomes a satellite of the Sun.
As it approaches us in December, astronomers hope to be able to observe its structure, thereby confirming its origin as noted above.
In November 1969, Apollo 12 landed near Surveyor 3, which had successfully landed 2 on the Moon the year before. In the photo is astronaut Al Bean standing next to the lander. They have disassembled it into parts to bring it back to Earth for review.
There have been a number of instances of old space hardware flying across the Earth and initially mistaken for a meteorite. In addition, our planet used to have some temporary moons. The 2020 CD3 meteorite orbited the Earth for several years before dropping away in early 2020. Another meteorite, 2006RH120, orbited Earth for several months in 2006/2007. Another object (only 20cm wide) has also burned in our atmosphere like a shooting star after having been around Earth for a while.
These objects are nicknamed “minimoon”, while the technical term is “temporarily captured objects” (TCOs). They are a minus point of aerospace engineering, but quite interesting. Will we be able to send a spaceship on one of these someday soon, since their velocity relative to us is quite slow, making them an easy target ?
But what surprise would it be if, like 2020 SO, that minimoon turns out to be a used upper deck of a past space mission, rather than a meteorite? Scientists will be disappointed, but there will certainly be very interesting technical data there – for example, corrosion due to exposure to the solar wind, or the impact of microflora – that rocket scientists are incredibly coveted. And if that was indeed a meteorite, wouldn’t that be too bad?
Let’s wait, because in just a few weeks, we will learn more about the mysterious visitor from that dimension.