Chilly, tiny, sans atmosphere

Like a B-list nightclub mid-week, Pluto's tiny sister planet Makemake is uninhabited, has "no notable atmosphere" - and ice to spare. A new study published in Nature has given the first glimpses into Makemake's makeup.

Makemake is one of the four tiny dwarf planets beyond Neptune whose discovery helped lead to Pluto's relegation out of the official list of solar system planets. Pluto was the first of the foursome to be spotted. A new study suggests that, unlike Pluto, Makemake does not possess a planet-wide atmosphere.

The authors of the report, published in the prominent journal "Nature" on November 21, observed the tiny, icy planet at an opportune moment and found evidence suggesting that the planet has only local pockets of atmosphere, if any at all.

Sudden blackout argues against atmosphere

The scientists established that Makemake had no global atmosphere by observing its effect on the light of another star that the planet was temporarily obscuring. A gaseous atmosphere would have begun to obscure the star's light before the planet aligned and blocked out the star altogether – but instead, the star disappeared quickly.

"At the end of the coverage, the star reappeared just as abruptly. That means that this dwarf planet cannot have any notable atmosphere," lead researcher Jose Luis Ortiz said. "Until now we had presumed that there were very good chances for the existence of an atmosphere. The fact that this is not the case just reinforces how much we still have to learn about these mysterious objects."

Dedicated to a deity

Makemake is named after the Great Sea Spirit of Easter Island, the prime creator god worshipped by the remote Polynesian population off the South American coast. It's named after the deity's reputation for fertility and sexuality - the astronomer who found it, Mike Brown, was celebrating news he would become a father at the time - and because it was spotted on the 283rd anniversary of Easter Island's discovery.

A barren, icy wasteland with temperatures not that far above absolute zero - at around negative 240 degrees Celsius (negative 400 degrees Fahrenheit) - it doesn't even appear to have any moons for company, again unlike Pluto. The notoriously mysterious population of Easter Island is poorly understood to this day, offering at least one similarity to the distant orb.

The study was also used to better estimate the planet's density - something that had not previously been calculated.

The research paper, which used readings from several major telescopes including the Very Large Telescope in Chile's Atacama Dessert, was entitled "Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation," with 25 researchers and more credited as co-authors.

msh/kms (AP)