• MY BLOG
  • BOOKS & ARTICLES
    • Books by Andrew Fraknoi
    • Articles for the Public
    • Articles for Educators
    • Classroom Activities on Astronomy
  • RESOURCE GUIDES
  • CONSULTING
    • Non-technical Talks on Astronomy
    • Developing Resource Guides
    • Writing Web-based Articles
    • Giving Talks on Astronomy Education
  • CLASSES & LECTURES
    • Classes I Teach
    • Silicon Valley Astronomy Lecture Series
    • Public Lectures I Give
  • GALLERIES
    • Solar System Images
    • Nebula and Galaxy Images
    • Bumper Stickers for Astronomy
    • Pictures with Astronomers
  • AUDIO & VIDEO
    • Radio Programs & Podcasts with Andrew Fraknoi
    • Videos of Talks and Interviews
  • SCIENCE FICTION
Type and hit ENTER

Be Yourself. Be Happy.

Of the grand order of folio leviathans, the Sperm Whale and the Right Whale are by far the most noteworthy. They are the only whales regularly hunted by man. To the Nantucketer, they present the two extremes of all the known varieties of the whale. As the external difference between them is mainly observable in their heads; and as a head of each is this moment hanging from the Pequod's side.

Stay Positive. Always.

Of the grand order of folio leviathans, the Sperm Whale and the Right Whale are by far the most noteworthy. They are the only whales regularly hunted by man. To the Nantucketer, they present the two extremes of all the known varieties of the whale. As the external difference between them is mainly observable in their heads; and as a head of each is this moment hanging from the Pequod's side.

  • MY BLOG
  • BOOKS & ARTICLES
    • Books by Andrew Fraknoi
    • Articles for the Public
    • Articles for Educators
    • Classroom Activities on Astronomy
  • RESOURCE GUIDES
  • CONSULTING
    • Non-technical Talks on Astronomy
    • Developing Resource Guides
    • Writing Web-based Articles
    • Giving Talks on Astronomy Education
  • CLASSES & LECTURES
    • Classes I Teach
    • Silicon Valley Astronomy Lecture Series
    • Public Lectures I Give
  • GALLERY
  • AUDIO & VIDEO
    • Radio Programs & Podcasts with Andrew Fraknoi
    • Videos of Talks and Interviews
  • SCIENCE FICTION
GET CONNECTED
  • MY BLOG
  • BOOKS & ARTICLES
    • Books by Andrew Fraknoi
    • Articles for the Public
    • Articles for Educators
    • Interdisciplinary Articles (Astronomy & the Humanities)
    • Classroom Activities on Astronomy
  • RESOURCE GUIDES
  • CONSULTING
    • Non-technical Talks on Astronomy
    • Developing Resource Guides
    • Writing Web-based Articles
    • Giving Talks on Astronomy Education
    • Organizing Conferences or Workshops
  • CLASSES & LECTURES
    • Classes I Teach
    • Silicon Valley Astronomy Lecture Series
    • Public Lectures I Give
  • GALLERIES
    • Solar System Images
    • Nebula and Galaxy Images
    • Bumper Stickers for Astronomy
    • Pictures with Astronomers
  • AUDIO & VIDEO
    • Radio Programs & Podcasts with Andrew Fraknoi
    • Videos of Talks and Interviews
  • SCIENCE FICTION
5,000 Planets Orbiting other Stars — and Counting!
Share
Astronomy, Exoplanets

5,000 Planets Orbiting other Stars — and Counting!

March 31, 2022
-
Posted by Andrew Fraknoi

NASA announced this week that their archive of confirmed “exoplanets” — planets going around stars other than the Sun — now contains 5,000 confirmed worlds. This is an astounding number, given that in 1990, the number of known planets orbiting stars outside our own solar system was zero. And more planets are being discovered all the time.

Remarkably, only 4% of the planets we have discovered so far are Earth-like — in that they are small, rocky worlds. 30% are giant planets like Jupiter, made of gas and liquid. 35% are colder “ice giants,” like Neptune in our solar system. And a full 31% are not like any of the planets we know locally. They are “super-Earths” — bigger than our home world, yet smaller than Neptune. This is a new in-between category which we are just starting to learn about. Some may be solid, like Earth, while others may be made of slush, liquid and gas.

Partly, the lack of earth-like planets is what scientists call a “selection effect.” Such small worlds are much harder to find. Our methods of discovering planets are much better at finding big ones than small ones, so it’s no surprise that our first surveys have turned up more big planets and tipped the statistics. As our instruments for planet discovery get better, we fully expect to find more Earth-sized worlds.

Even some of the planets that resemble ones we know can have odd twists to them. For example, in our neighborhood, planets like Jupiter orbit far from the Sun and are cold worlds, where future visitors would have to bring lots of insulating layers. But many Jupiter-like worlds we are finding turn out to be “hot Jupiters” — big planets orbiting so close to their home stars that their outer atmospheres are actually boiling away.

We’ve also found several planets that are orbiting two close-by stars at the same time, sort of like the planet Tatooine in the “Star Wars” films. Apparently, when two stars form at the same time in close proximity, it is possible for material around them to make stable planets that go around the pair.

What a rich selection of worlds we have already found, in the first 30 years of searching — and we have mostly searched stars in our immediate cosmic neighborhood. From the numbers we are finding nearby, astronomers estimate that the total number of planets in our home Milky Way Galaxy is likely to be on the order of 100 billion. That’s a lot of places for the Starship Enterprise to make stops!

March 31, 2022

Related Posts

Other posts that you should not miss.
Asteroids, Astronomy, Comets

First Visitor from the Realm of the Stars Ever Found Is Oddly Shaped

December 6, 2017
-
Posted by Andrew Fraknoi

Astronomers around the world have been observing a small but fast object that gives every indication of coming …

Read More
December 6, 2017
Posted by Andrew Fraknoi
Full Moon, Lick Observatory
Astronomy, Moon, Sky Phenomena

New Year’s Day Full Moon will be a “Supermoon”

December 30, 2017
-
Posted by Andrew Fraknoi

     By a cosmic coincidence, the first day of 2018 will have a nice full Moon …

Read More
December 30, 2017
Posted by Andrew Fraknoi
lunar eclipse, eclipse of the Moon,
Astronomy, Eclipse, Moon, Sky Phenomena

Total Eclipse of a Blue Supermoon on January 31

January 26, 2018
-
Posted by Andrew Fraknoi

On Wednesday morning, January 31, residents of North America (and particularly those on the west coast) will experience …

Read More
January 26, 2018
Posted by Andrew Fraknoi
← PREVIOUS POST
My New Science Fiction Story Published
NEXT POST →
Celebrating Pluto Day on the Radio

"*" indicates required fields

Subscribe to my blog!

Name*
This field is for validation purposes and should be left unchanged.

RECENT POSTS
  • We see the 128 new moons of Saturn with their orbits drwan in
    128 New Moons Found Around Saturn
    April 8, 2025

    An international team of astronomers announced recently that they had discovered 128 new, small …

  • Three images of the Moon during an eclipse
    Total Eclipse of the Moon Coming Mar. 13-14
    February 13, 2025

    There will be a total eclipse of the Moon visible in the Americas the night of March 13-14

  • Edwin Hubble
    Celebrating the Centennial of Galaxies January 1 2025
    December 29, 2024

    On January 1, 1925, at a meeting of the American Astronomical Society in Washington, …

  • Diagram showing Earth's tilt and the seasons
    Dec. 21 is Winter Solstice — Why We Have Seasons on Earth
    December 19, 2024

    Saturday, Dec. 21 will be the winter solstice – the shortest day and longest …

  • Anything can be a UFO (or a threatening drone) if you are bad enough at identifying stuff.
    Drone Madness: Here is the Antidote
    December 15, 2024

    For those of us who, through the years, have been through wave after wave …

Archives
  • HOME
  • ABOUT ME
  • CONTACT ME
  • FAVORITE LINKS

© Copyright 2025 | All Rights Reserved

5,000 Planets Orbiting other Stars - and Counting! - Andrew Fraknoi - Astronomy Lectures - Astronomy Education Resources