Peptide chain formation from amino acids such as glycine is a key step in the emergence of life. Unlike their synthesis by living systems, how peptide chains grow under abiotic conditions is an open question given the variety of organic compounds discovered in various astrophysical environments, comets and meteorites. We propose a new abiotic route in the presence of protonated molecular dimers of glycine in a cold gaseous atmosphere without further need for a solid catalytic substrate. The results provide evidence for the preferential formation of mixed protonated dimers of glycine consisting of a dipeptide and a glycine molecule instead of pure protonated glycine dimers. Additional measurements mimicking a cosmic-ray impact in terms of internal excitation show that a single gas-phase collision induces polymerization via dehydration in both the mixed and pure dimer ions.

Based on analysis of preliminary information from several sources, NASA experts believe the object was a meteoroid about two feet in diameter weighing about 1,000 pounds. The angle and speed of entry, along with signatures in weather radar imagery, are consistent with other naturally occurring meteorite falls. Radar and other data indicate that meteorites did reach the ground from this event.

Although meteorites tend to hit Earth’s atmosphere at high speeds, they slow as they travel through the atmosphere, breaking into small fragments before hitting the ground. Meteorites cool rapidly and generally are not a risk to the public.

On Feb. 3, an asteroid more than three times as long as it is wide safely flew past Earth at a distance of about 1.1 million miles (1.8 million kilometers, or a little under five times the distance between the Moon and Earth). While there was no risk of the asteroid—called 2011 AG5—impacting our planet, scientists at NASA’s Jet Propulsion Laboratory in Southern California closely tracked the object, making invaluable observations to help determine its size, rotation, surface details, and, most notably, shape.

This close approach provided the first opportunity to take a detailed look at the asteroid since it was discovered in 2011, revealing an object about 1,600 feet (500 meters) long and about 500 feet (150 meters) wide—dimensions comparable to the Empire State Building. The powerful 230-foot (70-meter) Goldstone Solar System Radar antenna dish at the Deep Space Network’s facility near Barstow, California, revealed the dimensions of this extremely elongated asteroid.

“Of the 1,040 near-Earth objects observed by planetary radar to date, this is one of the most elongated we’ve seen,” said Lance Benner, principal scientist at JPL who helped lead the observations.