ClassX Video Lessons Youtube Channel Curiosity Stream Are There Signs of Life On Other Planets? | Breakthrough
Exciting news has emerged from the world of astronomy! Dr. Mikel Gon and his team have used the Spitzer Space Telescope to discover seven Earth-sized planets orbiting a star called TRAPPIST-1, located about 40 light years away from us. Out of these seven planets, three are in the “habitable zone,” where conditions might allow liquid water to exist on their surfaces. This discovery is groundbreaking because it suggests that finding another Earth-like planet is not just a question of “if,” but “when.”
With advancements in technology, we can now explore distant parts of the universe to answer one of humanity’s biggest questions: Are we alone? In the past, we only knew about the nine planets in our solar system. Today, we understand that there are more planets than stars in the universe. Each star has one or more planets, known as exoplanets, orbiting it. NASA’s discovery of multiple Earth-like exoplanets around a single star is a significant milestone.
This discovery didn’t happen overnight. Two years before NASA’s announcement, scientists at the European Southern Observatory identified the TRAPPIST-1 star and two Earth-like planets orbiting it. Later, NASA’s Spitzer Telescope confirmed an additional five planets. TRAPPIST-1 is an ultracool dwarf star, which means it shines more brightly in infrared light than visible light. This made it perfect for Spitzer, an infrared telescope, to study.
Instead of taking pictures of these planets, scientists observe how much the star’s light dims when a planet passes in front of it. This helps them determine the size of the planet. By measuring the time between these dimming events, they can calculate the planets’ orbits and masses. The closest planet, TRAPPIST-1b, orbits the star every 1.5 days, while the farthest, TRAPPIST-1h, takes about 20 days. These planets range from 75% to 115% the size of Earth, suggesting they could be rocky like our planet.
The planets in the habitable zone are particularly intriguing for the search for life. One of these planets might have a water-rich composition, which is very promising. These planets are so close to their star that they are likely tidally locked, meaning one side always faces the star, experiencing constant daylight, while the other side is in perpetual night. If you were on one of these planets, you would have an incredible view of the others, unlike how we see Venus or Mars as small dots in the sky.
Unlike our solar system, the TRAPPIST-1 planets don’t seem to have moons, and their star is much cooler than our sun. This allows the planets to orbit closer to the star than Mercury does to our sun. However, cooler temperatures don’t guarantee life. Young stars can be very active, which might have affected the atmospheres of these planets when the star was younger.
Most stars in our galaxy are M dwarfs, like TRAPPIST-1. They burn their hydrogen fuel slowly, lasting for billions of years, which could provide ample time for life to evolve on orbiting planets. However, whether life can develop depends on the planet’s position within the habitable zone.
In our solar system, Venus and Mars mark the edges of the habitable zone. Venus is too hot, while Mars is too cold. The TRAPPIST-1 system might be more forgiving. The innermost planet in the habitable zone, TRAPPIST-1e, is similar in size to Earth and receives a comparable amount of light, suggesting it might have Earth-like temperatures. TRAPPIST-1f, potentially rich in water, has a 9-day orbit and receives sunlight similar to Mars. TRAPPIST-1g, the largest, receives sunlight between Mars and the asteroid belt.
This discovery is a major step forward in the search for habitable worlds and life beyond Earth. We now have several candidates to study, increasing our chances of finding life-friendly conditions. While we know the masses, sizes, and orbits of these planets, much remains to be learned.
Spitzer’s discovery is historic, even though it wasn’t originally designed to find exoplanets. That task was for NASA’s Kepler spacecraft, which has identified a record number of exoplanets. In 2016, Kepler discovered 1,284 exoplanets, with 21 in their stars’ habitable zones, potentially suitable for life. This has transformed our understanding of planets and their formation.
In 2011, Kepler found Kepler-16b, the first confirmed planet orbiting two stars. Kepler-452b, an Earth-sized planet in the habitable zone, is 1,400 light years away. In 2016, the same observatory that discovered TRAPPIST-1 may have found Proxima b, a planet 30% larger than Earth, orbiting its star’s habitable zone just 4.4 light years away.
While current technology isn’t ready for a flyby, Proxima b could be the first stop in exoplanet exploration. Its proximity allows for the possibility of building specialized instruments to study it, potentially gathering data on its atmosphere and observing its phases as it orbits.
Proxima b has become a hot topic among planetary scientists. If you lived there, you would experience either constant daylight or perpetual night, with limited habitable conditions. As we continue to explore these questions, the future of discovering life beyond Earth looks promising and exciting.
Using materials like foam balls, string, and paint, create a scale model of the TRAPPIST-1 system. Label each planet and indicate which ones are in the habitable zone. This hands-on activity will help you visualize the arrangement and scale of the planets in relation to their star.
Conduct research on M dwarf stars and their significance in the search for life beyond Earth. Prepare a short presentation to share with the class, highlighting why these stars are important and how they differ from our Sun. This will deepen your understanding of stellar types and their potential to host habitable planets.
Participate in a simulation of the transit method used to detect exoplanets. Use a light source and small objects to mimic how scientists observe the dimming of a star’s light when a planet passes in front of it. This activity will give you insight into the techniques astronomers use to discover new worlds.
Engage in a class debate on the topic: “Is it likely that life exists on exoplanets?” Use evidence from recent discoveries, such as the TRAPPIST-1 system, to support your arguments. This will enhance your critical thinking and ability to evaluate scientific evidence.
Imagine you are an astronaut on a mission to one of the TRAPPIST-1 planets. Write a short story about your journey and what you discover upon arrival. This creative exercise will allow you to explore the possibilities of life on other planets and express your understanding of the topic in a narrative form.
I’m excited to announce today that Dr. Mikel Gon and his team have used the Spitzer Space Telescope to determine that there are actually seven Earth-sized planets orbiting the nearby star TRAPPIST-1, located about 40 light years away. Three of these planets, marked in green, are in the habitable zone where liquid water could exist on the surface. In fact, with the right atmospheric conditions, there could be water on any of these planets. This discovery marks the first time we have found as many terrestrial planets around a single star, suggesting that finding a second Earth is not just a matter of if, but when.
As technology continues to bring the deep cosmos within reach, we can now explore the most unlikely places in hopes of answering one existential question: Are we alone? When I was a student, we knew about nine planets, and that was it. Today, we can say that statistically, there are more planets out there than stars. Every star has one or more planets, known as exoplanets, orbiting it. NASA has made a groundbreaking discovery of multiple Earth-like exoplanets surrounding a single star.
This cosmic jackpot wasn’t discovered overnight. Two years before NASA’s announcement, scientists at the European Southern Observatory pointed their telescope 39 light years from our solar system and confirmed a new star, now known as TRAPPIST-1, along with two Earth-like exoplanets in its orbit. However, it wasn’t until NASA’s Spitzer Telescope was aimed at the system that an additional five exoplanets were confirmed.
TRAPPIST-1 is classified as an ultracool dwarf star, which means it is much brighter in the infrared spectrum than in visible light, making it ideal for Spitzer, an infrared telescope, to conduct follow-up observations. We don’t image the individual planets; instead, we observe the amount of light that the star dims when a planet passes in front of it. The size of the dip in light tells us the size of the planet. By measuring the spacing between these transits, we can determine the orbital period and, consequently, the mass of the planets.
We have determined that the closest planet, TRAPPIST-1b, orbits its star every 1.5 days, while the farthest, TRAPPIST-1h, completes its orbit in roughly 20 days. The planets’ sizes range from 75% to 115% of Earth’s size, indicating they could all be rocky bodies. The planets in the habitable zone are particularly promising for the search for life beyond our solar system. For one of these planets, our measurements strongly suggest a water-rich composition, which is very exciting.
These planets are so close to their star that they are likely tidally locked, meaning they always face the star with one side experiencing permanent daylight and the other permanent night. An exciting aspect of this system is that the planets are so close to each other that if you were on the surface of one, you would have a spectacular view of the others, unlike how we see Venus or Mars as mere dots of light.
Unlike our solar system, the planets surrounding TRAPPIST-1 do not appear to have any moons, and its star is much cooler than our sun. TRAPPIST-1’s lower temperatures allow the planets to orbit at a distance closer than Mercury orbits our sun, but lower temperatures do not necessarily guarantee the presence of life. Young stars can be very active, which raises concerns about whether the atmospheres of these potentially habitable planets were eroded when the star was younger.
Most stars in our galaxy are M dwarfs, and they burn their hydrogen fuel slowly, lasting for tens of billions of years. If a planet orbits such a star, there may be ample time for evolution to occur. However, evolution depends on the planet’s location within the habitable zone.
In our solar system, Earth’s neighbors, Venus and Mars, mark the edge of our habitable zone. Venus is an inferno due to its proximity to the sun, while Mars is a cold desert. The TRAPPIST-1 system may be more forgiving. If we zoom out to the system, we see all seven planets, with the habitable zone indicated in blue. The innermost planet in the habitable zone, TRAPPIST-1e, is very close in size to Earth and receives a similar amount of light. This suggests that temperatures on TRAPPIST-1e could be very similar to those on Earth.
The next planet, TRAPPIST-1f, is potentially water-rich and has a 9-day orbit, receiving about the same amount of sunlight as Mars. The final planet in the habitable zone, TRAPPIST-1g, is the largest in the system, about 133% the size of Earth, and receives sunlight somewhere between Mars and the asteroid belt.
With this discovery, we’ve made a significant leap forward in the search for habitable worlds and life beyond our own. We now have multiple candidates to study, which increases our chances of finding conditions suitable for life. While we currently know the masses, sizes, and orbits of these planets, much remains to be learned.
Spitzer’s monumental discovery is historic, but its original mission did not involve searching for exoplanets; it was designed to survey the universe using infrared light. The task of discovering exoplanets was assigned to NASA’s Kepler spacecraft, which has scanned over 150,000 stars and identified a record-breaking number of exoplanets.
In 2016, Kepler identified 1,284 exoplanets, over half of its total discoveries. Among these, 21 planets are in their stars’ habitable zones and are thought to be the right size for life. This has revolutionized our understanding of planets and their formation.
In 2011, Kepler observed Kepler-16b, the first confirmed planet orbiting two stars, while Kepler-452b, an Earth-sized planet in the habitable zone, is 1,400 light years away. In 2016, the same observatory that discovered the TRAPPIST-1 system may have found a more accessible candidate: Proxima b, which is believed to be 30% larger than Earth and orbits its star’s habitable zone at a distance of 4.4 light years.
While current technologies are not yet prepared for a flyby, Proxima b could potentially become the first stop in exoplanet exploration. The proximity of Proxima Centauri allows for the possibility of building specialized instruments to study the planet, potentially allowing us to gather spectral data and observe its phases as it orbits.
Proxima b has become a hot topic for planetary scientists worldwide. If you lived on Proxima b, you would experience either constant daylight or perpetual night, with limited habitable conditions on the surface. These questions about whether we are alone are being explored as we speak, and I’m truly excited about what the future holds.
Planets – Celestial bodies that orbit a star, are massive enough to be rounded by their own gravity, and have cleared their orbital path of other debris. – The eight planets in our solar system each have unique characteristics and compositions.
Life – The condition that distinguishes living organisms from inorganic matter, including the capacity for growth, reproduction, and continual change preceding death. – Scientists are searching for signs of life on Mars by analyzing soil samples and atmospheric conditions.
Habitable – Capable of supporting life, typically referring to environments where conditions allow for the presence of liquid water, a stable atmosphere, and suitable temperatures. – The discovery of a potentially habitable exoplanet has sparked interest in the possibility of finding extraterrestrial life.
Astronomy – The scientific study of celestial objects, space, and the universe as a whole. – Astronomy has advanced significantly with the development of powerful telescopes that allow us to observe distant galaxies.
Exoplanets – Planets that orbit stars outside our solar system. – The Kepler Space Telescope has identified thousands of exoplanets, expanding our understanding of planetary systems beyond our own.
Discovery – The act of finding or learning something for the first time, often leading to new knowledge or understanding. – The discovery of gravitational waves has opened a new era in the field of astronomy, allowing scientists to study cosmic events in unprecedented ways.
Orbiting – The action of moving around a celestial body in a curved path, typically due to gravitational forces. – The Hubble Space Telescope is orbiting Earth, providing valuable data about the universe.
Water – A vital chemical compound (H2O) that is essential for life as we know it and is often a key indicator in the search for habitable planets. – The presence of water ice on Europa, one of Jupiter’s moons, suggests the potential for an ocean beneath its icy surface.
Stars – Luminous celestial bodies made of plasma, held together by gravity, and generating energy through nuclear fusion. – Stars like our Sun are the primary sources of light and energy for their respective solar systems.
Technology – The application of scientific knowledge for practical purposes, especially in industry, including the development of tools and machines. – Advances in technology have enabled astronomers to detect exoplanets by measuring the tiny dimming of stars as planets pass in front of them.
