Snap Asteroid Eros and Help Measure the Size of the Solar System

Join Our Community of Science Lovers!

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Fed up of simply reading about space and want to do some real science? Well, here's your chance: astronomers are asking anyone with a pair of binoculars or telescope to train them on a new object visible in the night sky.

The object is an asteroid called 433 Eros. At 20 miles wide it's one of the largest near-Earth asteroids, but it only really gets close to use once every 1.76 years because of it's highly elliptical orbit. Its about to get the closest to Earth that its been in over thirty years – but don't worry, at 16.6 million miles away it won't pose any threat.

In fact, it could prove useful. From now until this Friday, the Eros Parallax Project is asking anyone with the right equipment to snap photos of Eros at specific times depending on their location. If you're quick, you might be able to jump on board and help. There's more information about the project here.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Depending on where you are on Earth, you will see Eros in a slightly different place in the sky relative to the background stars. This phenomenon is known as parallax. You can see it if you hold a finger up at arms length, look at where it is relative to the background with one eye closed, then switch eyes and watch it shift in relation to whatever is behind it.

Astronomers will use all the data submitted to find the distance to Eros. They will then use this to get a better estimate of the size of the solar system.

Kelly Oakes has a master's degree in science communication and a degree in physics, both from Imperial College London. She started this blog so she could share some amazing stories about space, astrophysics, particle physics and more with other people, and partly so she could explore those stories herself.

More by Kelly Oakes

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe