To date we've confirmed 1,821 planets outside of our solar system.
In 1989, there were zero.
And I think it's fair to say, we've learned a few things since then.
Hey planetoids, Trace here for DNews.
In 1584, a Catholic Monk, Giordano Bruno claimed there were "countless suns and countless Earths."
More than 400 years later, in a 1995 book on exoplanets three scientists wrote, "The
detection and study of Earth-like planets outside our Solar System will be one of the
great scientific, technological and philosophical events of our time."
Because even with so much time in between, no earth-like planets had been confirmed!
A decade later, the first earth-like planet, Gliese 581 C, was discovered; and as of March
2015, we've confirmed 29 water-holding habitable, earth-like planets; and calculations say there
might be BILLIONS more,.
Do you feel like you live in the era of a huge scientific, technological and philosophical
event?
You should!
There's a huge database of possible candidates and confirmed exoplanets, and as we observe
OTHER solar systems we're learning things about how OUR solar system works.
New research in the Proceedings of the National Academy of Sciences used other solar systems
as a model for our own.
Our solar system was formed from leftovers after the Big Bang, gas and dust coalesced
into planets over many many millions of years.
OTHER solar systems have supermassive exoplanets closer to their sun, but we don't.
Scientists believe Jupiter was the reason ours looks different.
They believe, Jupiter USED to be closer to the sun, and tacked outward, dragging all
the junk from the inner solar system with it.
When the solar system first formed, there were planetesimals, or small planetary building
blocks, flying around in the inner solar system where Mercury, Venus, Earth, and Mars are
now.
While today, Jupiter orbits at about 5 AUs, it used to range from 3 to 10!
All that motion cleared the way like a wrecking ball.
It could have even destroyed any other proto-planets which formed before the four inner planets
we have now.
This Wandering Jupiter hypothesis isn't the perfect explanation for why we look different,
but it hits a lot of checkboxes on the way to a good theory.
Keeping an eye on the sky has also helped us feel a little less alone.
A study in the Astrophysical Journal found Kepler 444, a solar system which has five
Earth-like planets orbiting it in a way very similar to our own -- AND it's 11.4 billion
years old, meaning those planets were formed long before ours and are relatively similar
in size.
The problem is, they're too close to their star, orbiting in only around 10 days -- Mercury
orbits in 84 days.
So, while 444 doesn't have life, it shows planets can form really FAST, and that's USEFUL
because there might be life-capable planets with a billion-year head start on us out there!
The Kepler telescope was launched in 2009 to search for exoplanets and, in case you've
forgotten, KEPLER is BROKEN and is STILL finding them.
The Milky Way has between 100 and 400 billion stars -- that's a lot of places to point a
telescope.
The more we learn, the more scientists can make educated guesses and point telescopes
at the right stars.
It might be blazé to say it, but I'm pretty sure, finding other planets really is the
most scientific, technological and philosophical event that you never think about.
And we really should think about it more, because it teaches us so much about our own!