In 1994 our solar system had Earth and 7 other planets, only 8 altogether that we could “prove.” On Apr. 19, 2013, beyond our solar system
871 planets have now been identified, 3 just recently!
(Based on USA Today‘s report-Apr.20, 2013–of recent Kepler Telescope findings & The Extrasolar Planets Encyclopaedia)
How to think about this? What do we really know? Use the DOOR.
First, in case you missed it, in 2006 Pluto was “demoted” as being a true planet, leaving 8 in our solar system. Also, there was no mutually agreed-upon evidence for “exoplanets” (planets beyond our solar system) until 1995. Now we can make a case for 871 planets. Our planet knowledge is now (as of Apr. 19) like this:
Date Known Planets
1994 8 (not counting demoted Pluto)
2013 871 (as of Apr. 19)
Some Generalizations and Logical Questions
1. The universe is very, very large.
2. Complex telescopes have been hard at work with new technology.
3. An overwhelming number of these planets are large gaseous balls (think of Jupiter in our solar system).
4. Very, very few are approximately the size and composition of Earth.
5. And of these, very, very few seem to have a “Goldilocks zone,” which is astronomy jargon for having “just right,” neither “too hot or too cold” temperatures, and all other necessary materials and conditions, for any life to exist. (And human life is very demanding!)
6. How far away are these planets? Hugh Ross gives this illustration: Suppose a star is the size of a grapefruit and is located in Los Angeles. Using average distances between stars, the next closest “grapefruit/star” would be in Peru. And stars are the suns that these exoplanets revolve around.
7. How do we know such things about objects so far away? Astronomers have fancy ways of measuring and analyzing starlight and detecting tiny changes in brightness of stars.
8. Okay, so what are the names of these 3 new planets? Kepler-62e, Kepler-62f, and Kepler 69-c (which is 70% bigger than Earth). Kepler-62 (that’s the star itself) was described as “nearby” to us since it is only 1,200 light years away. That’s 708,000 trillion miles. In other words, it takes light 1,200 years for light to get from there to here, or that the light we’re seeing is 1,200 years old. (Flash: As of Apr. 23 the number of planets jumped by 1 to 872! I don’t know the name for the last planet.)
9. Anything else? The Earth rotates around its star (the sun) in about 365 days. For the 3 planets listed in #8, the lengths of their years are 122 days, 267 days, and 242 days respectively.
10. Tell me something else I don’t know. Okay, the length of a year on Planet Emryss is 420 days, and the only confirmation of this is reported in “The Secret of Zareba” in my book, Earth Is Not Alone listed on the right column of this website. (Warning: A single observation of anything calls for caution…)
[♠] Hmsch: Information about, and names of, stars and planets are easy to locate on the Internet. Why not make a chart of some of this information to put on the wall to remind yourself of how big the universe is and some of the new things going on in astronomy? Bonus: Are there any parallels between the star Mira and the character Mira in “The Secret of Zareba” (part of EINA, mentioned above).