“Astronomers have discovered the first known system to host seven Earth-size planets around one star, and it lies just 39 light-years away from our own solar system.” – Space.com
Unless you live under a rock, you heard this week that NASA disclosed a groundbreaking discovery regarding the TRAPPIST-1 system, containing 7 Earth-like planning potentially supporting life. Anticipation was mounting from the 24 hours before the announcement was going to be made, and when it did occur, there was a bombardment of articles/videos about it everywhere you could look. Justifiably so, the discovery (more of a confirmation of what was already known, but we’ll call it a discovery) set the record for most habitable exoplanets found in a system or something crazy like that (don’t quote me on that!).
![]() |
This is an Artist’s representation of what the views from the planets may look like. |
Here’s the breakdown:
Brief:
TRAPPIST-1 is a star like our sun, but cooler (I’m talking about temperature) and smaller. Known as an ‘ultra cool dwarf’ star, it currently has 7 Earth like bodies orbiting it. The reason this has been blown out of proportions is because of the nature of media today, majorly sensational and looking for the next headline to lure readers/viewers in. While the discovery is truly monumental, I’m going to have to burst the bubble and put things into perspective a little.
The system is approximated to be ~40 light years away. Getting there? Piece of cake.
Piece of difficult cake.
A light year is a monstrous distance, and even that is an understatement. A light year, by definition is the distance light will travel in vacuum in one year. To put it in perspective, in one second light can travel around the equator of Earth. Seven times.
You get the idea. It’s unlikely we’ll be visiting them anytime soon, but we shouldn’t just give up.
![]() |
A comparison of TRAPPIST-1’s planets and our solar system’s rocky planets. |
How the discovery was made:
TRAPPIST is a telescope (Transiting Planets and Planetesimals Small Telescope) which is operated by the ESO’s La Silla observatory.
TRAPPIST is controlled from Liege, Belgium, with some autonomous features. It is a reflecting telescope 0.60 m (23.5″) in aperture diameter and is housed in the dome of the retired Swiss T70 telescope. – Wikipedia
A team of Astronomers and scientists used the TRAPPIST scope to observe the ultra cool dwarf star 2MASS J23062928-0502285, now named TRAPPIST-1. By using a method known as Transit Photometry, they identified and recorded 3 planets innermost to the star in the habitable zone of it.
![]() How they apply Transit Photometry: |
“Detailed characterization — and the search for signs of possible life, such as oxygen and methane — will have to wait until more powerful instruments come online, Triaud said. But that wait shouldn’t be long: NASA’s $8.8 billion James Webb Space Telescope is slated to launch in late 2018, and huge, capable ground-based scopes such as the European Extremely Large Telescope and the Giant Magellan Telescope are scheduled to come online in the early to mid-2020s.” – Space.com
“All the planets in the TRAPPIST-1 system transit their star, meaning that they pass in front of it. The planets were discovered from the regular and repeated shadows that are cast during transit. Thanks to the transit signals we could measure the orbital periods of the planets and could calculate the sizes of the planets. The exact time at which the planets transit also provide us with a means to measure their masses, which leads to knowing their densities and therefore their bulk properties. The planets are consistent with a rocky composition. We found that the planets have sizes and masses comparable to the Earth and Venus. Because we know the distance of the planets to their star, and the temperature of the star, we can deduce that they receive an amount of light that is similar to many of the planets in the Solar system, from Mercury to beyond Mars.“
Conclusion