ClassX Video Lessons Youtube Channel Curiosity Stream Are We Truly Alone In The Universe? | A Curious World
One of the biggest mysteries of our time is whether we are alone in the universe. Out in the vastness of space, there are planets that might be similar to Earth, orbiting stars with the right conditions for life. Thanks to advanced science and new telescopes, we are getting closer to solving this mystery. Scientists are on a great detective hunt to answer one of humanity’s most intriguing questions.
On a clear night, far from city lights, you can see the Milky Way galaxy, filled with countless stars. These stars are actually suns, and about 22% of them might have planets that could support life. A team of astronomers from California and Hawaii discovered this by analyzing data from the Kepler telescope, launched in 2009. Kepler’s mission was to find Earth-like planets around other stars by looking for dimming light, which indicates a planet passing in front of its star.
There could be around 100 billion billion Earth-like planets in the universe. Even if just a tiny fraction of these planets developed intelligent life, there could be millions of intelligent civilizations out there. Kepler and the Hubble telescope have changed how we understand the universe, sparking excitement about the possibility of life on other planets.
For over 50 years, scientists have been searching for signs of life beyond Earth. They started with radio telescopes, hoping to pick up signals from intelligent beings. We’ve also sent our own signals into space through TV broadcasts and satellites, but haven’t heard back yet. Today, scientists use advanced telescopes and robotic probes to find conditions that might support life.
To understand what makes life possible, we look at Earth. Three key ingredients are needed: basic elements like carbon and oxygen, a liquid like water to mix these elements, and an energy source like the sun to power life. On Earth, life exists in extreme places, like deep under Antarctic ice or near hydrothermal vents in the ocean. If life can survive here, it might exist in similar environments elsewhere.
Mars, our closest neighbor, is a major focus in the search for life. Images from Mars missions suggest that water once flowed on its surface. Although the water seems to have disappeared billions of years ago, there might still be enough trapped in polar ice caps to cover the planet. NASA’s Curiosity Rover found more water in Mars’ frozen soil, offering hope for life on the Red Planet.
Further away, Jupiter’s moon Europa is a promising candidate for life. Beneath its icy surface lies a vast ocean, possibly warmed by volcanic activity. NASA plans to launch a mission to Europa by 2025 to explore this possibility.
Scientists are developing new tools to find planets. NASA and MIT are working on the Transiting Exoplanet Survey Satellite (TESS), set to launch in 2017. TESS will search for exoplanets—small planets with bright stars—and catalog them for future study. In 2018, the James Webb Telescope will launch, offering more powerful observations than the Hubble. Its ability to view infrared light will help scientists study alien atmospheres for signs of life.
Finding an Earth twin—a planet like ours—is challenging due to bright starlight. NASA is developing a starshade to block this light, allowing telescopes to see exoplanets more clearly. If successful, the starshade will launch with a telescope in 2023.
With billions of galaxies and countless planets, the search for extraterrestrial life is more thrilling than ever. The possibility of life beyond Earth is becoming more real, bringing us closer to answering the age-old question: Are we truly alone in the universe?
On a clear night, gather with your classmates and a teacher to observe the night sky. Use a telescope or binoculars to identify different stars and constellations. Discuss how astronomers use telescopes like Kepler to discover planets around these stars. Try to imagine which stars might have planets that could support life.
Using art supplies, create a model of a planet that could support life. Consider the key ingredients for life: basic elements, liquid water, and an energy source. Present your planet to the class, explaining why it might be a good candidate for life and what kind of life forms might exist there.
Work in groups to design a simple rover using materials like cardboard, wheels, and small motors. Create a “Martian” landscape in your classroom and navigate your rover through it. Discuss the challenges of exploring Mars and what scientists hope to discover about water and life on the planet.
Learn about how scientists use radio telescopes to search for extraterrestrial signals. Set up a simple experiment using a radio receiver to pick up signals from different sources. Discuss what kind of signals we might expect from intelligent life and why we haven’t received any yet.
Choose a future space mission, such as the James Webb Telescope or the Europa mission, and research its goals and technology. Create a presentation for the class, explaining how this mission could help us find life beyond Earth and what challenges it might face.
**Sanitized Transcript:**
[Music] It’s one of the world’s greatest mysteries: hidden in the vastness of space are planets similar to Earth, orbiting a sun with just the right conditions for life to exist. Cutting-edge science and a new generation of telescopes are providing powerful new tools to expand our understanding of deep space. The greatest detective hunt in history is underway to answer one of humankind’s most elusive questions.
Far away from city lights, on a stretch of barren road, you can look up on a cloudless, moonless night and see a breathtaking view of our Milky Way galaxy, with what looks like hundreds of thousands, maybe even billions, of stars. It’s an awe-inspiring sight. But take a second look: those stars are actually suns, and nearly 9 billion of them—22% of all the stars in our galaxy—may have planets that could potentially support life.
That’s what a team of astronomers from California and Hawaii has recently uncovered. They analyzed data from Kepler, a high-powered space-based telescope launched in 2009. Kepler’s mission was to search for potentially habitable, Earth-like planets around other stars. The Planet Hunters surveyed 442,000 sun-like stars, just a tiny fraction of our galaxy, looking for a well-known clue: the dimming light caused by an orbiting planet as it crosses between the parent star and us.
By some estimates, there are around 100 billion billion Earth-like planets in the universe. Conservatively, if 1% of 1% of those planets developed intelligent life, we could be looking at 10 million billion intelligent civilizations. Kepler, along with the far-seeing Hubble telescope, has transformed our understanding of the universe. The idea that there could be so many small, rocky planets with the possibility of life is stirring excitement in the space community and beyond.
Scientists have been looking for evidence of life for over 50 years, since the first radio telescopes were used to scan for a signature of intelligence. We’ve sent signals of our own into the cosmos with TV broadcasts and satellite transmissions, but so far, there has been no reply. Today’s astronomers and scientists aren’t searching for space aliens from some advanced civilization; instead, they’re using sophisticated optical telescopes and robotic probes to find the conditions that might be conducive for life.
Because Earth is the only planet we know of where life exists, a look at what made it all possible is a critical starting point. Three key ingredients are needed: basic building block elements like carbon, oxygen, hydrogen, and nitrogen; a liquid like water so these elements can mix and create more complex organic compounds; and an energy source like the sun to power the chemical reactions needed to drive life, from the tiniest microbes to human beings.
On Earth, life is found in some of the most remote places. Traces of DNA were recently discovered in ice cores buried miles under an Antarctic ice sheet, and in the pitch-black depths of our oceans, hydrothermal vents have been found teeming with life, from blind shrimp to tube worms. If life can survive here, we might be able to find it in other extreme environments.
Our closest neighbor, Mars, has been a major focus in our search for life. Satellite imagery from several Mars missions has boosted the theory that water once flowed on its surface. Scientists say this dense network of gullies could be from ancient rivers that formed from rain or melting snow. However, that liquid water appears to have vanished billions of years ago when the planet cooled and the atmosphere largely disappeared. But scientists estimate there may be enough water trapped in its polar ice caps to cover the entire planet with an ocean 80 feet deep. When NASA’s Curiosity Rover touched down on the Martian surface, it found more water trapped in the planet’s frozen soil, which is a hopeful sign for the possibility of life on Mars.
But hundreds of millions of miles away, one of Jupiter’s moons, Europa, is currently NASA’s best bet for life. Under its icy crust is an enormous ocean where bacterial life might be found, especially if active volcanoes beneath Europa’s surface heat the water. However, we’ll have to wait at least a decade to find out; NASA hopes to launch a mission to Europa by 2025.
Scientists are already hard at work creating the planet-hunting instruments of tomorrow. A joint effort between NASA and MIT will launch the Transiting Exoplanet Survey Satellite (TESS) in 2017. TESS will spend two years looking for exoplanets—small planets with bright host stars—and cataloging them for future exploration. Next up, in 2018, will be the launch of the James Webb Telescope, NASA’s next-generation premier space observatory. The telescope’s 18 hexagonal mirrors measure 21.4 feet across, giving it much more light-gathering power than the Hubble telescope. The sharpness of its images will allow scientists to see a penny from 24 miles away.
One of the telescope’s most notable abilities will be to view infrared light. It will scan the atmospheres of alien planets for oxygen and other gases that could be produced by living organisms. However, searching for what might be considered an Earth twin—a planet of the same size and temperature as Earth—is a huge challenge. The bright light from nearby stars makes it almost impossible to see. One project NASA is developing is a giant starshade to help block the starlight so telescopes can better see exoplanets. If all goes well, the starshade will launch on a separate telescope in 2023.
With billions of galaxies and hundreds of billions of planets, the hunt for extraterrestrial life has never been more exciting. Life beyond Earth is finally coming closer into view.
Universe – The universe is the vast space that includes everything that exists, such as galaxies, stars, and planets. – Scientists study the universe to understand how galaxies and stars are formed.
Planets – Planets are large celestial bodies that orbit a star, like the Sun, and do not produce their own light. – Earth is one of the eight planets that revolve around the Sun in our solar system.
Life – Life refers to the existence of living organisms, which can be found in various forms on Earth and potentially on other planets. – Scientists are searching for signs of life on Mars by analyzing soil and rock samples.
Stars – Stars are massive, luminous spheres of plasma held together by gravity, emitting light and heat. – The Sun is the closest star to Earth and provides the energy necessary for life.
Telescope – A telescope is an instrument used to observe distant objects in space by collecting and magnifying light. – Astronomers use telescopes to study the surface of distant planets and stars.
Mars – Mars is the fourth planet from the Sun, known for its red color and potential to support life. – Rovers have been sent to Mars to gather data about its atmosphere and surface conditions.
Water – Water is a vital compound made of hydrogen and oxygen, essential for life as we know it. – The discovery of water on the Moon has sparked interest in future lunar missions.
Exploration – Exploration is the act of traveling through or investigating an unfamiliar area to learn more about it. – Space exploration has led to many discoveries about our solar system and beyond.
Signs – Signs are indications or evidence that suggest the presence or existence of something. – Scientists look for signs of past water flow on Mars to determine if it could have supported life.
Civilization – Civilization refers to a complex society with a developed culture and technology. – The search for extraterrestrial civilizations involves listening for signals from intelligent life forms in space.
