Asteroids are chunks of rock and metal left over from the formation of the solar system, smashed and shattered, and orbiting the sun everywhere, with the vast majority of asteroids between the orbits of Mars and Jupiter.
] The Hubble Space Telescope is an observatory orbiting the earth and looking at objects throughout the universe that are scattered all over the sky. Above the Earth's atmosphere, it has a darker sky and sharp vision, so it can look deep into space.
When you put these two things together, many asteroids in Hubble's observations come across.
This is actually a huge phenomenon of pain, for example, when trying to get extremely deep images of a cluster of galaxies. Asteroids leave stripes in the picture and confuse it. No wonder astronomers used to call them "vermin of the sky"!
But if you actually try to find asteroids and characterize their physical properties and orbits, then Hubble's archive is a treasure trove of data. However, there are thousands upon thousands of images, far too many for a handful of astronomers … and the tracks that leave asteroids in pictures are very hard to automatically identify for computers.
A group of astronomers have embarked on a project called Hubble Asteroid Hunter (as part of the larger Zooniverse project), where non-astronomers can log in, view Hubble imagery, and identify asteroids in the observations , This kind of thing is called Citizen Science, and it is remarkable how little training is required to get really good results from non-scientists. There are many such projects (including the observation of craters on the moon and large asteroids, spiral galaxies to determine which direction they are facing, and much more), and it generally only takes a few minutes to get to the people to use them, use them.
In this case, volunteers were looking for the project to gently curved stripes of light. Hubble circles the earth orbiting the sun, and at the same time the asteroid orbits the sun. During a long exposure, an asteroid appears to move in the image, leaving a streak, but all these movements together curl the streak in different ways.
Hubble Asteroid Hunter was launched in the last week of June 201
The nice thing is that Hubble's images were specially selected because software predicted they might contain an asteroid. Once an asteroid with a ground-based telescope has been discovered, observations made over many weeks or months can be used to get a good overview of its orbit. This can then be used to calculate where it will be in the future and where it has been in the past. If his path was through a Hubble field of view during observation, that asteroid could be seen from the observatory. It is not 100% certain that the calculation of the orbit has some uncertainty and it is possible that the asteroid has passed outside of Hubble's view.
Nevertheless, the volunteers have found many asteroids. Hubble's observations are so good that it makes it possible to significantly increase the orbit measurements and thus better understand the position of the asteroids. Since a small part of it could get close to the earth and a smaller part could hit us, this is a good thing.
Many years ago, when I was working on Hubble, I found an asteroid in one of our pictures. I was so excited! I could retrieve some basic data about it and hoped that I could name it … but unfortunately reality had other plans. You can read this story in an article I wrote some time ago. I still smile sadly every now and then about this day.
But I am glad that so many asteroids could be better characterized with this project! This is important work. I also wonder how many small, as yet undiscovered asteroids are included in these images (like the ones I found) too weak for follow-up and too short a span of observation to get an adequate orbit measurement for them – Observations are usually made At least many days to calculate the shape of the track.
Maybe this is a task for another time. This project is a good start and I am interested in finding out the results when they are published. And I hope that can be extended to any observatory that manages its observations in a searchable database. It's a very big sky, and the more eyes we have on it, the better.