NASA Discovers New Batch of Earthlike Planets

SCIENCE

NASA’s Kepler spacecraft has shaken its one-thousandth planet from the sky. Eight new worlds beyond our solar system boost the number of Kepler’s confirmed planets to 1,004 (if you’re keeping count). (National Geographic News)

What is a planet? Use our resources to find out!

Teachers, scroll down for a short list of key resources in our Teachers’ Toolkit.

Of the more than 1,000 verified planets found by NASA's Kepler Space Telescope, eight are less than twice Earth-size and in their stars' habitable zone. All eight orbit stars cooler and smaller than our sun. The search continues for Earth-size/habitable-zone worlds around sun-like stars. Illustration courtesy NASA, of course! Read their press release about Kepler's new discoveries here.

Of the more than 1,000 verified planets found by NASA’s Kepler Space Telescope, eight are less than twice Earth-size and in their stars’ habitable zone. All eight orbit stars cooler and smaller than our sun. 
Illustration courtesy NASA, of course! Read their press release about Kepler’s new discoveries here.

Discussion Ideas

  • Kepler, NASA’s amazing mission to search for planets outside our solar system, just found more “Earthlike” planets—bringing the number to about 8 out of 1,004. Astrophysicists think Earthlike planets are rocky and lie in the “habitable zone” of their own planetary systems. (Most of the rest are so-called “hot Jupiters.” Read more about those weird planets here.) What is a “habitable zone”?
    • A habitable zone is a region around a star where conditions can support liquid water on the planet’s surface.

 

  • Why is liquid water necessary for a planet to be considered “habitable”? This fantastic essay from the brainiacs at NOVA Online gives some great reasons.
    • Why liquid?
      • The biochemical reactions that sustain life need a fluid in order to operate. In a liquid, molecules can dissolve and chemical reactions occur. [Liquid also] effectively conveys vital substances . . . from one place to another, whether it’s around a cell, an organism, an ecosystem, or a planet.
    • Why water?
      • Water is [one of] our only naturally occurring inorganic liquids, the only one not arising from organic growth.
      • Water dissolves just about anything.
      • Water is the only chemical compound that occurs naturally on Earth’s surface in all three physical states: solid, liquid, and gas. Good thing, otherwise the hydrological cycle that most living things rely on to ferry water from the oceans to the land and back again would not exist.
      • Water also has an extremely large liquid range. Pure water freezes at 0°C (32°F) and boils at 100°C (212°F). Add salt and you can lower the freezing temperature. Add pressure and you can raise the boiling temperature. . . [This means that temperatures] can undergo extreme variations—between night and day, say, or between seasons—without water freezing or boiling away.
      • Unlike most other liquids when they freeze, water expands and becomes less dense. [Frozen water floats, not sinks.] If it sank, ice, being unable to melt because of the insulating layer of water above it, would slowly fill up lakes and oceans in cold climates, making sea life in those parts of the world a challenging prospect.
      • Water plays another key role in the biochemistry of life: bending enzymes. Enzymes are proteins that catalyze chemical reactions, making them occur much faster than they otherwise would. To do their handiwork, enzymes must take on a specific three-dimensional shape. Never mind how, but it is water molecules that facilitate this.
    • Take it from rock star astrophysicist Neil deGrasse Tyson: “Given that life on Earth is so dependent on water, and given that water is so prevalent in the universe, we don’t feel that we’re going out on a limb to say that life would require liquid water.”

 

Kepler 186f was the first Earth-sized planet orbiting a star in a habitable zone. Kepler 186f is part of a five-planet system orbiting a dwarf star about half the size and mass of the sun. (Earth is part of an eight-planet system orbiting a star exactly the size and mass of the sun.) Learn more about Kepler 186f here. Illustration courtesy NASA Ames/SETI Institute/JPL-Caltech

Kepler 186f was the first Earth-sized planet orbiting a star in a habitable zone. Kepler 186f is part of a five-planet system orbiting a dwarf star about half the size and mass of the sun. (Earth is part of an eight-planet system orbiting a star exactly the size and mass of the sun.) Learn more about Kepler 186f here.
Illustration courtesy NASA Ames/SETI Institute/JPL-Caltech

  • What are some conditions that may put a planet in the “habitable zone”? Why do astrophysicists nickname these elusive conditions the “Goldilocks zone”?

 

Kepler is our first real search for planets orbiting other stars. The sun is just one out of more than 200 billion stars in our galaxy, the Milky Way. Kepler will be examining more than 100,000 stars in our galactic neighborhood. Most of these stars will be at least 500 light years from our solar system. (That's 2,939,312,686,591,803 (almost three quadrillion) miles. And those are our neighbors.) Illustration by Jon Lomberg, www.jonlomberg.com, courtesy NASA

Kepler is our first real search for planets orbiting other stars. The sun is just one out of more than 200 billion stars in our galaxy, the Milky Way. Kepler will be examining more than 100,000 stars in our galactic neighborhood. Most of these stars will be at least 500 light years from our solar system. (That’s 2,939,312,686,591,803 (almost three quadrillion) miles. And those are our neighbors.)
Illustration by Jon Lomberg, http://www.jonlomberg.com, courtesy NASA

 

TEACHERS’ TOOLKIT

Nat Geo: NASA’s Kepler Spacecraft Discovers New Batch of Earthlike Planets

Nat Geo: What is a planet?

NOVA: Life’s Little Essential

Nat Geo: Exploring Alien Oceans: Kevin Hand Talks About the Search for Life in Space’s Frozen Oceans

(extra credit! NASA: Exoplanet Archive)

6 responses to “NASA Discovers New Batch of Earthlike Planets

  1. Pingback: Nearby Exoplanet May Be Habitable | Nat Geo Education Blog·

  2. Pingback: Gorgeous New Galactic ‘Growth Chart’ | Nat Geo Education Blog·

  3. Pingback: Weekly Warm-Up: What it Means to be Frozen in Space | Nat Geo Education Blog·

  4. Cool!!!

    *Cindi Valgento
    Economics and American History
    Apache Junction High School

    “I am much struck these days by the fact that certain powerful critics call both for the abandonment of social studies as a discipline and the solution of those social problems which only the social studies can analyze and solve. The more precarious our position becomes, the more we are needed.”

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