Astronomers might have been looking for alien life in all the wrong places, according to new research.
A team from the University of Cambridge in the UK has identified a new class of planet that is very different to Earth but could still support life.
These planets, known as hycean planets, are ocean-covered worlds that are up to 2.6 times larger than Earth and have hydrogen-rich* atmospheres* and temperatures up to almost 200C.
Scientists have mostly focused their search for alien life on planets of a similar size, temperature and atmosphere to Earth.
This has made sense because Earth is the only planet we know of that has life.
But now the University of Cambridge team believes there are more promising possibilities out there when it comes to finding life beyond our own solar system.
The researchers said hycean planets were more common and easier to observe than Earth-like planets, and this could lead to the discovery of microscopic* life within the next few years.
“Hycean planets open a whole new avenue in our search for life elsewhere,” said Dr Nikku Madhusudhan from Cambridge’s Institute of Astronomy, who led the research.
Many of the main hycean planets identified by the researchers are bigger and hotter than Earth, but still have the characteristics* to host large oceans that could support microbial* life similar to that found in some of Earth’s most extreme aquatic environments.
The researchers have identified a “sizeable sample” of hycean planets for further investigation. These planets orbit small, dim stars called red dwarfs, between 35 and 150 light-years from Earth.
Signs of life on the planets could be picked up by a new generation of telescopes, such as NASA’s James Webb Space Telescope, which is due to be launched into orbit later this year.
The research, reported in The Astrophysical Journal, found conditions on hycean planets meant it would be easier to detect “biosignatures”, which is a fancy term for signs of life.
“A biosignature detection would transform our understanding of life in the universe,” Dr Madhusudhan said.
“We need to be open about where we expect to find life and what form that life could take, as nature continues to surprise us in often unimaginable ways.”
GLOSSARY
- hydrogen-rich: containing a lot of hydrogen, a gas which is essential for life
- atmosphere: the gases or air that surrounds planets
- microscopic: so small it is visible only using a microscope
- characteristics: features or qualities
- microbial: to do with microbes, which are very small living things
EXTRA READING
The planets better suited for life than Earth
Scan of 10.3 million stars doesn’t find aliens – yet
Chirps from space reach Earth again
36 alien races could live in Milky Way
QUICK QUIZ
- Which university conducted this research?
- What are the new type of planets called?
- What covers these planets?
- How much bigger than Earth as some of these planets?
- How many light years from Earth are these planets?
LISTEN TO THIS STORY
CLASSROOM ACTIVITIES
1. Planet comparison
Draw a side-by-side picture of Earth and a hycean planet. Your picture should show the difference in size and appearance. Label each planet with information about the atmosphere and temperatures. (You may need to do a little research for this.) Add any extra information that you think is important or interesting.
Time: allow 25 minutes to complete this activity
Curriculum Links: English; Mathematics; Science
2. Extension
Write a sentence that gives the main idea of this news story. Your sentence must include these Tier 3 words: hycean, microbial, biosignatures
Time: allow 10 minutes to complete this activity
Curriculum Links: English; Science
VCOP ACTIVITY
Opener Up-Level It
Make a list of all the openers in the article. Pick three that repeat and see if you can replace them with another word, or shuffle the order of the sentence to bring a new opener to the front.
Don’t forget to re-read the sentence to make sure it still makes sense, and that it actually sounds better.
