Planetary Formation in the News

Planetary formation made the news in three different ways this week. Find out how surprising results from studies of a meteorite, a debris field and the planet Venus all shed new light on our own planet’s deep history.

Back in public school, everyone in my class had an oversized atlas in our desks with a blue-black cover. On the cover was a map of solar system, from the Sun all the way out to Pluto, tracing the elliptical orbit of each planet in light blue.

The world was caught up in the Space Race at the time, and planets were a hot topic. TV shows like Star Trek and Lost in Space reinforced our youthful fascination with worlds beyond Earth.

We take the existence of other planets for granted in the 21st century. We say things like, “he looked at me as if I was from another planet” as if we know what people from other planets are like.

Astronomers Have Now Discovered Over 5,000 Planets

Our matter-of-fact attitude isn’t surprising, since astronomers have now discovered over 5,000 planets in our galaxy. What’s remarkable is how little we know about how planets form.

Scientists call their most accepted theory on planetary formation the nebular hypothesis. The idea is that when stars form out of gas clouds, they’re surrounded by a disc-shaped cloud of debris. That debris seems to gradually clump together into planets like those in our solar system.

Planetary science was in the news several times this week. As usual in astronomy, to paraphrase J. B. S. Haldane, the findings were “not only queerer than we suppose, but queerer than we can suppose.”

Meteorite from the Interior of the Planet Mars

The journal Science published a study of the Chassigny Meteorite from the interior of the planet Mars. It landed in northeastern France in 1815.

Since it came from inside Mars, the team expected this vintage meteorite could tell them more about planetary formation in the case of Mars. It did, but not in the way they expected.