Down to Earth With: Planetary geologist James W. Head III

In the late 1960s, as James W. Head III was finishing his graduate degree in geology at Brown University in Providence, R.I., he decided one day to take a look at a college placement annual, a phone book-like publication that listed prospective employers according to the types of jobs they had available. When Head looked up geology in the index, he saw several consecutive pages of related listings, as well as one separate page number. Curious about the outlier, Head flipped to it — and never looked back. Covering that entire page was a photo of the moon, a D.C.-area phone number, and a single line of text: “Our job is to think our way to the moon and back.”

29 Mar 2017

Red Planet Roundup: February 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

14 Feb 2017

Mystery impact may have kicked off dramatic warming event

About 56 million years ago, the planet warmed rapidly in a mysterious event known as the Paleocene-Eocene Thermal Maximum (PETM). Researchers recently discovered evidence in the rock record from around the same time that points to an extraterrestrial impactor striking Earth, but whether the two events are related is yet to be determined.

06 Feb 2017

Benchmarks: January 31, 1961: Ham the chimpanzee, first hominid in space

Early on the morning of Jan. 31, 1961, a chimpanzee named Ham, outfitted in a diaper, waterproof pants and a space suit, was sealed into a capsule and loaded onto a Mercury-Redstone 2 spacecraft in Cape Canaveral, Fla. Six hours later, Ham the Chimp, named after Holloman Aeromedical Research Laboratory at Holloman Air Force Base in Alamogordo, N.M., where he was trained, became the first hominid to travel into space.

31 Jan 2017

Moon formed from pulverized Earth mantle

Scientists have long thought that the moon was formed when an impactor crashed into Earth, some 100 million years after the planet’s formation. But details of this collision, and how the moon formed in its aftermath, remain puzzling. Now, researchers have found new potassium isotopic evidence that suggests the moon condensed from a superheated cloud of Earth’s mantle material after an extremely violent collision vaporized the impactor and much of the proto-Earth.

23 Jan 2017

Mercury's recent tectonics revealed

Not so long ago, Mercury was the least-studied planet in the inner solar system, known only from Earth-based observations and from Mariner 10’s brief flyby in the 1970s. In 2011, the MESSENGER spacecraft began orbiting Mercury, imaging the planet’s crater- and fault-scarred surface before crashing into it, as planned, in 2015. As MESSENGER spiraled downward, it took a last series of high-resolution images, analyses of which are revealing new information about the planet’s surface geology, including evidence for recent tectonic activity.

05 Jan 2017

Cosmic suntan

An international team of astronomers recently measured the amount of light hitting Earth that comes from outside our galaxy across a broad range of wavelengths.

22 Dec 2016

Newly discovered Earth-like worlds are rocky, not gassy

In May, a new planetary system was discovered just 40 light-years from Earth, including three Earth-sized planets orbiting around their red dwarf sun in a temperature range that could potentially harbor life. Now, a follow-up study on the system has found that the two innermost planets are primarily rocky with compact atmospheres, as opposed to inhospitable gas giants, like Jupiter.

15 Nov 2016

Pluto may still have liquid ocean

Last year, images from NASA’s New Horizons flyby of Pluto revealed geologic activity that suggested a liquid ocean may have once lurked beneath the dwarf planet’s icy crust. But whether it still exists in that state, or had frozen, remained a question. According to a new study published in Geophysical Research Letters, it may still be partially liquid.

14 Nov 2016

Dust orbiting Jupiter is going the wrong way

Periodically, micrometeoroids strike one of the four Galilean moons of Jupiter — Io, Europa, Ganymede and Callisto — sending dust into space, some of which enters into orbit around the gas giant. Recently, researchers charting the dusts’ orbits spotted some peculiar patterns, including some particles orbiting Jupiter in a retrograde fashion, by circling, when viewed from above, clockwise rather than counterclockwise.

03 Nov 2016