Skip to Content
Space

Earth’s “fingerprint” could one day help us find a habitable exoplanet

September 2, 2019
kepler-186f
kepler-186fNASA/Ames

The telltale signature that Earth’s atmosphere produces when it passes in front of the sun could help us find out if other worlds are potentially habitable. 

Stellar signs: When a planet “transits” its host star (passes in front of it from Earth’s vantage point), the particle chemistry of the planet’s atmosphere scatters, absorbs, and refracts the starlight in very specific ways. You can use these transits to confirm the presence of things like water vapor or the amount of gases like oxygen and carbon dioxide. You can even detect biosignatures like methane or other organic compounds that hint at the presence of extraterrestrial life.  

The technology: Two astronomers, based at McGill University in Montreal, pored over data collected by the Canadian Space Agency’s SCISAT satellite, which was originally launched to help us better understand Earth’s ozone depletion. Since 2004, SCISAT has made continuous observation of the light that passes through the atmosphere when Earth is in front of the sun. The researchers used this data to simulate what the entire planet’s transit spectrum looks like in infrared light, something that’s never been done before. The findings were published last week in the Monthly Notices of the Royal Astronomical Society.

Why it matters: Earth’s “fingerprint” gives clues into what we ought to look for as we study other exoplanet transits in greater detail and attempt to confirm their potential habitability, such as in the TRAPPIST-1 system. The researchers are particularly bullish that the successor to Hubble, the James Webb Space Telescope, will be an invaluable tool for this type of work when it’s finally operational in just a few years.

Keep Reading

Most Popular

This startup wants to copy you into an embryo for organ harvesting

With plans to create realistic synthetic embryos, grown in jars, Renewal Bio is on a journey to the horizon of science and ethics.

VR is as good as psychedelics at helping people reach transcendence

On key metrics, a VR experience elicited a response indistinguishable from subjects who took medium doses of LSD or magic mushrooms.

This nanoparticle could be the key to a universal covid vaccine

Ending the covid pandemic might well require a vaccine that protects against any new strains. Researchers may have found a strategy that will work.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.