Month: October 2019

Simple chemicals can grow complex pretty quickly.

There's a strong consensus that life on Earth got its start through RNA, a close chemical sibling of DNA. Over the last few decades, researchers have described how individual RNA bases can spontaneously polymerize, forming longer chains that could ultimately catalyze key chemical reactions, including building even longer RNA molecules. As a result, it's clear that RNA can perform two functions: carrying heritable genetic information just as DNA does and carrying out the instructions encoded by that information.

There's far less agreement, however, on how those RNA bases themselves first form. These bases have a combination of one of two types of flat, ringed structures linked to a small, ring-shaped sugar. Over time, researchers have found sets of chemical reactions that could start with simple chemicals likely to be found on the early Earth and end up with one of the three more complex chemicals needed to form RNA. But the conditions needed for these reactions weren't compatible, raising questions about how an RNA molecule could ever form from these reactions.

Now, a group of chemists has figured out a way to form the portions of RNA that give it its identity starting from a simple set of chemicals. The work relies on materials that can easily be provided by a volcanic environment. And driving the reactions forward requires little more than a few wet/dry cycles.

Enlarge / The first image returned by Luna 3 to Earth. (credit: Wikimedia)

To the extent that most people think about spaceflight before NASA's Apollo program, they probably remember the flights of Yuri Gagarin or Alan Shepard, or perhaps the launch of Sputnik on this date in 1957. But between Sputnik and the first human launches, the Soviet Union flew a lunar exploration program that was remarkable for its time.

In 1959, the Soviet Luna program launched three missions that, to one degree or another, were successful. Luna 1 became the first spacecraft to enter a heliocentric orbit, Luna 2 struck the Moon, and Luna 3—quite incredibly, for the time—captured photos of the far side of the Moon and returned them to Earth. This final mission, Luna 3, launched sixty years ago today on a converted intercontinental ballistic missile from the Baikonur Cosmodrome.

To understand the magnitude of this success, recall that most satellites launched during this era failed to reach orbit successfully. At the time, the United States had only launched about half a dozen satellites into orbit around the Earth, and most of these weighed between 10 and 20kg. By October, 1959, the United States had attempted to launch four spacecraft toward the Moon. Three had not come close. One, Juno II, passed within 60,000km of the Moon in 1958.