TechSimilarity to Earth: Precise measurement of a nearby planet

Similarity to Earth: Precise measurement of a nearby planet

Visualization of exoplanet LTT 1445Ac
Visualization of exoplanet LTT 1445Ac
Images source: © NASA, ESA, L. Hustak (STScI)

9:56 AM EST, November 18, 2023

The Hubble Telescope has facilitated the precise measurement of the nearest exoplanet that resembles Earth. This particular object is not too distant from our planet.

With the Hubble Space Telescope, astronomers were able to determine the size of an Earth-like exoplanet, which is in proximity. This planet orbits the star LTT 1445A, part of a system of three red dwarfs located 22 light-years away from our planet. To put it into perspective, the Alpha Centauri system, which is our closest neighbor, is just over four light-years away.

As reported on the Urania website, the small planet LTT 1445Ac was first discovered by the TESS satellite in 2022 using the Hubble Telescope. However, a precise measurement was impossible at the time due to the limited optical resolution of TESS.

"The system could have had an unfavorable geometry, making it difficult to accurately measure its size. However, with the capabilities of the Hubble Space Telescope, we were able to precisely measure the diameter of this planet," said Emily Pass from the Center for Astrophysics | Harvard & Smithsonian, in Cambridge, Massachusetts. She is also the author of the published article in the Astronomical Journal.

A mirror image of Earth?

The planet LTT 1445Ac is slightly larger compared to our planet - its diameter is only 1.07 times that of Earth. This finding suggests that it is a rocky object experiencing a similar surface gravity as Earth.

However, it can't sustain life as we know it, as the surface of the planet reaches a temperature of approximately 500 degrees Fahrenheit.

"Transiting planets are particularly intriguing as they enable us to characterize their atmospheres using spectroscopy techniques. This can be achieved not only with the Hubble Telescope, but also with the James Webb Space Telescope. The current measurements are significant as they suggest that the planet LTT 1445Ac is likely very similar to Earth. We eagerly await further observations that will provide greater insight into the diversity of planets orbiting other stars," commented Pass, as quoted by the Urania website's editorial staff.

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