About C.C. Petersen

I am a science writer and media producer specializing in astronomy and space science content. This blog contains news and views about these topics.

Kepler in Search of Distant Earths

A Near-Earth-size Planet Isn’t Necessarily JUST Like Earth

A artist's concept of Kepler-452b, a near-Earth-sized planet discovered by the Kepler space telescope. Courtesy NASA/Kepler

A artist’s concept of Kepler-452b, a near-Earth-sized planet discovered by the Kepler space telescope. Courtesy NASA/Kepler

The news last week that the Kepler telescope had found a close “cousin” of Earth circling a sun-like star really brought out the speculation among people who don’t actually study planets for a living. The press, of course, ran with the story, calling it “Earth 2.0″ and “Earth-like”, neither of which is quite true. However, despite the tendency of supermarket rags as well as serious press to jump on stories like this and carry them to illogical extremes, the discovery of this planet IS a milestone in exoplanet research.

Kepler-452b IS likely to be a rocky world similar to Earth, although astronomers haven’t confirmed that yet. It’s in the habitable zone of its star, so that means liquid water could exist on its surface. Whether it has water, or even an atmosphere, is all still to be determined. This planet is near-Earth-size, meaning it’s close to our planet’s size. Actually, it’s 60 percent larger than Earth, and its 385-day year is slightly longer than our 365-day year. It’s about a billion and a half years older than Earth, which has interesting implications for the evolution of life. Life began on Earth some 3.8 billion years ago, and this new planet has had a LOT longer than that to cook up some life.

Still, that’s not enough to make it Earth 2.0.


For that to happen, we’ll need to know more about its atmosphere — including finding any telltale tracers for life. The planet’s star is very much like our Sun, and in the grand scheme of things, since life evolved to take advantage of what the Sun has to offer, it will be interesting to find out, someday in the distant future, what sort of life Kepler-452b has got on its surface.

All of us who read science fiction know about the countless worlds that populate the stories we read. Many times they ARE Earth-like, but supporting entirely different forms of life than what we have here. That makes sense — the universe is the ultimate generator of infinite diversity in infinite combinations. The boundary conditions — that is, the starting collection of compounds from which life can arise — may well be slightly different from what we know here on Earth. Or, it could be a LOT different. And those differences all but guarantee that life elsewhere isn’t going to look like us.

But, it’s fun to think about life elsewhere as we gaze at a starlit sky, or browse through the artist’s concepts of worlds that Kepler and its partner observatories have found. That’s the sort of stuff that keeps us going, striving to explore ever further out in the galaxy. It’s what we do.

Classifying My Thoughts about Pluto

Pluto and the Myth of a Planetary Status Vote

Pluto is a fascinating world; it's teaching us more about the hidden third realm of the solar system than any other place we know of. Courtesy NASA/JHUAPL/SWRI

Pluto is a fascinating world; it’s teaching us more about the hidden third realm of the solar system than any other place we know of. Courtesy NASA/JHUAPL/SWRI

In the days since we got back from the events surrounding Pluto Encounter, I’ve been thinking a lot about the issue of planetary status for our newly explored friend in the Kuiper Belt. I know a lot of people are signing petitions to get Pluto’s planetary status returned to “planet”, and at the same time the planetary scientists involved in New Horizons data are falling in love with Pluto and analyzing their treasure trove of actual, scientific information.

Of course, Pluto is the realm of planetary scientists. They’re the ones who have the qualifications to figure out what it is and what it’s doing. I’ve always thought that having a tiny percentage of people decide on something as fundamental as Pluto’s status when they weren’t all planetary scientists was the height of arrogance by the IAU. That organization encouraged a “vote” and a “decision” on something that had less to do with scientific inquiry and more (I suspect) to do with politics.

Since when do we VOTE on science facts? That’s a Republican Party kind of thing, sort of like voting to substitute myths for sound government policy, or to make pi equal to 3, or to reduce adult women to the legal equivalent of children when it comes to making their own scientific medical care decisions.

It’s a myth that you get to vote on planetary status. How is that scientific?

I mean, did IAU members vote on “star” or “galaxy”? What about “gravity”? Or “gas laws”? Or any of the other givens of science? Do they want to redefine Maxwell’s equations as “writings by some Scotsman”? They’d still be equations, right? Of course, that would be stupid. And arrogant. I dare say, if they decided that dwarf stars aren’t stars, the astronomers would be all over the IAU “leadership” like a cheap suit in nothing flat. It should be the same with “planet” and all its ramifications for what worlds are.

I’m not a member of IAU (they say no doctorate=no membership, no matter how well-educated in astronomy someone may be). So, I can look in from the outside and speculate about how silly it looked to vote on Pluto’s planetary status. As if it meant something to science.

Yes, I get that we use characteristics to define objects in the universe. Definitions are part of science. I get that and approve of it. But, voting on science? I don’t think so.

What’s important about Pluto is what that little world tells us. It’s a unique place. It has an evolutionary history that we’re still figuring out. It has mountains and an active atmosphere and ice flows and maybe even a subsurface ocean. Its processes are amazingly fascinating. And, it’s all happening in a place in the solar system where many scientists thought there might be just a dead world with an icy covering.

Pluto is the runaway surprise hit of the solar system. It’s bigger than our puny attempts to define it, to fit it into a single bin and forget about it. Pluto has something to show us, and is a HUGE piece in the puzzle of understanding our solar system and how ALL its components formed. THAT is something the IAU cannot take away.

So, let’s put this myth about voting over planetary status to rest. Let’s focus on what Pluto IS, and what it’s going to tell us. It’s opening the door to the third realm of the solar system. Like all those Europeans who once thought the Eastern shores of North America were all there was of the “new world”, the IAU can vote all it wants to define Pluto. But, I suspect Pluto will give us MORE than we ever expected. And, in the end science will win.