A THOUSAND Worlds and Counting!

This week, the number of exoplanets reached 1, 010! It's been more than 20 years--1992, to be exact-- since the first confirmed extrasolar planet (a.k.a. a planet outside our solar system). Since then, the tools have vastly improved from Earth-based telescopes that had to contend with atmospheric interference to space-based ones like the Kepler telescope which has been racking up finds since 2009. 

The field of exoplanet research has expanded beyond just locating planets, it now encompasses classification--separating the gas giants from the rocky abodes--in the hopes that another Earth-like planet might be found.

As of today, eight candidates have been identified as being in the "Goldilock's Zone" of their respective parent stars (i.e., sustainable temperature for liquid water), where life--at least as we know it on Earth--might have the best chance to thrive. 

In the meantime, the bounty of alien worlds has been plentiful. From NBC News:

Indeed, the current tally is likely just the tip of the exoplanet iceberg. For example, a study published last year estimated that every star in the Milky Way hosts 1.6 planets on average — meaning that our galaxy likely harbors at least 160 billion alien worlds.

And those are just the planets with obvious parent stars. Another recent study calculated that "rogue planets" — those that cruise through space apparently unbound to any star — may outnumber "normal" worlds by 50 percent or so.

The number of confirmed planets should continue its dramatic upward swing in the near future as astronomers continue to hone their techniques and analyze data collected by instruments on the ground and in space. 

Here's to the search for an alien Earth and all the exoplanets yet to be discovered!

Update: Here's a nice little video recently put together by MIT, explaining some exoplanet basics:

 

More details:

• Astrobiology Magazine: Exoplanets: 1,000 and Counting
• BBC News: Exoplanet tally soars above 1,000
• NBC News: Hello worlds! Alien planet count passes 1,000 mark
• Universe Today: Changing the Paradigm: Exoplanet Interview with Dr. Sara Seager
• Exonauts Twitter feed - I typically link to exoplanet discoveries in the news there
• Exonauts Exoplanet page and blog post tags