The week also brought stories of literal revival — involving Little Ice Age plants and perhaps Big Ice Age woolly mammoths — photographs of chemical reactions, diminished radiation worries in Japan, and astronomy meeting social media.

Developments

Chemistry

Atoms, Rearranged

Scientists have captured images of atoms in motion, rearranging themselves in chemical reactions.

Taking a picture of an atom is a lot like reading Braille. The sharp tip of an atomic-force microscope rises and falls as it is dragged across the bumps on a surface — the atoms.

A team of researchers has now modified the technique, positioning a carbon monoxide molecule so that a single oxygen atom acted as a “finger” that felt not only carbon atoms, but also the chemical bonds between the atoms.

That allowed them to observe how a carbon-based molecule rearranged itself into other molecules when temperatures exceeded 194 degrees Fahrenheit.

Space Exploration

Travel, Irradiated

For the first humans who travel to Mars, the trade-off of fame and history will be a higher risk of dying from cancer.

NASA’s latest robotic spacecraft on the planet, the Curiosity rover, measured the radiation it encountered during its interplanetary trip. As expected, the radiation, mostly from cosmic rays from outside the galaxy, was several hundred times as intense as what reaches the surface of the Earth, scientists announced last week.

For astronauts making a round trip to Mars — six months each way using current rocket propulsion — that would correspond to a three-percentage-point increase in the lifetime risk of a fatal cancer.

Because Mars lacks a magnetic field or a thick atmosphere, astronauts would absorb additional radiation during their time on Mars’ surface.

Archaeology

A Gift From the Sky

Iron beads from 3300 B.C. found in Egypt turn out to have an older, more distant origin. They were made from a meteorite.

Excavated from a cemetery south of Cairo, the nine tube-shaped beads had a large amount of nickel, like iron meteorites, leading to speculation that they had been shaped out of extraterrestrial metal.

A new study confirms the high nickel content, along with a crystal structure found only in iron meteorites.

“Something that falls from the sky is going to be considered as a gift from the gods,” said Joyce Tyldesley, an archaeologist at the University of Manchester in England and an author of the study.

Biology

New Life From Old

With warming temperatures, a glacier on Ellesmere Island in northern Canada has been receding, exposing plants that had been trapped under ice since the Little Ice Age more than 400 years ago. But scientists noticed that some of the seemingly black, dead plants had small green growths. In the laboratory, they ground up some of the plant samples and sprinkled them over soil in petri dishes. Within months, resurrected plants sprouted.

Meanwhile, in Siberia, Russian scientists reported that they had extracted blood from the carcass of a woolly mammoth that had been frozen for 10,000 years, leading to speculation that the DNA might be preserved well enough to enable cloning of the extinct animal.

Engineering

Power From the Gulf (of Maine)

The first floating windmill in the United States went online Friday. Anchored in the Gulf of Maine, it will be able to capture the onshore breezes every sunny summer afternoon when the sun heats the land more than the ocean. Onshore wind machines generate most of their electricity at night, when it is of least use to utilities.

The prototype can generate only 20 kilowatts of electricity, but the University of Maine researchers who developed it hope it will lead to a 6-megawatt version with blades as long as the wingspan of a 747.

Environment

It Could Have Been Worse

Badly damaged by an earthquake and an ensuing tsunami in March 2011, the reactors at the Fukushima Daiichi nuclear power plant in Japan teetered on the brink of a major disaster. A new report, however, suggests that the effects were much less dire than had been feared.

In the report, published Thursday, experts on a United Nations committee say that people living around the plant received a radiation dose from the accident lower than what they get from natural background sources. There have also been no radiation-related deaths or acute effects observed among the 25,000 workers who were involved with the accident site.

Coming Up

Astronomy

Your Portrait Here (Look Up!)

For $25, that could be you floating in space.

Or more precisely, a picture of a picture of you floating in space. But for most of us, that is as close as we will ever get to orbit.

That is what you get in exchange for a $25 contribution to a $1 million fund-raising effort to build a private space telescope. As of Monday, the project was already most of the way there, with more than $700,000 raised, including 18 pledges of $10,000 or more.

A video monitor will be mounted on the orbiting telescope to display photographs of its backers. A camera will take pictures of the photos on the monitor with the Earth in the background, and beam the images back to Earth.

Planetary Resources, the company building the telescope, plans to eventually mine asteroids, and it has deep-pocketed investors like Larry Page of Google who could easily kick in $1 million themselves, but company officials said they wanted to give everyone a chance to take part in space exploration.

Thus they put their plans for their Arkyd-100 space telescope on Kickstarter, the crowdfunding Web site.

The drive ends June 30. At higher pledge levels, you could buy telescope time for a school classroom or point it yourself for your personal astronomical observations.