Astronomy Now Home
Home Magazine Resources Store

On Sale Now!



The October 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). Astronomy Now is the only astronomy magazine specially designed to be read on tablets and phones. Download the app from Google Play Store or the Apple App Store.



Top Stories



Earthshine used to test life detection method
...By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds...
  READ MORE

Solid buckyballs discovered in space
...Astronomers using NASA’s Spitzer Space Telescope have detected a particular type of molecule, given the nickname “buckyball”, in a solid form for the first time...
  READ MORE

Steamy water-world gets the Hubble treatment
...Hubble Space Telescope observations of a 7 Earth-mass planet find an unusual water-rich world swathed in a thick, steamy atmosphere...
  READ MORE








Haumea's spot rich with organics?
DR EMILY BALDWIN
ASTRONOMY NOW
Posted: September 16, 2009


Bookmark and Share

A dark red spot discovered on dwarf planet Haumea appears to be richer in minerals and organic compounds than the surrounding icy surface say scientists presenting their research at the European Planetary Science Congress today.

Haumea is a member of the dwarf planet family and orbits the Sun in the Kuiper Belt, which lies beyond the orbit of Neptune. Haumea is unusual because of its highly elongated shape – it measures approximately 2,000 by 1,600 by 1,000 kilometres – moulded by its extraordinary fast rotation rate of just one revolution every 3.9 hours. This characteristic is attributed to a massive impact collision more than a billion years ago.

Composite image of computer model frames showing Haumea's red spot as the dwarf planet rotates. Image: P Lacerda.

Previous studies of the dwarf planet imply that it has a density 2.5 times that of water. Spectroscopic observations reveal that Haumea is covered in water ice, so the high density suggests it must possess a rocky interior.

Astronomers discovered a mysterious spot on Haumea's surface by measuring changes in the tiny planet's brightness as it rotated. The resulting light curve, which describes variations in brightness over time, is not exactly the same shape in all wavelengths – small but persistent differences indicate that the dark spot is slightly redder in visible light and slightly bluer at infrared wavelengths.

“Our very first measurements of Haumea told us there was a spot on the surface," says Pedro Lacerda of Queen's University Belfast. "The two brightness maxima and the two minima of the light curve are not exactly equal, as would be expected from a uniform surface. This indicates the presence of a dark spot on the otherwise bright surface. But Haumea’s light curve has told us more and it was only when we got the infrared data that were we able to begin to understand what the spot might be.”

The scientists speculate that the spot could represent an enrichment of minerals and organic compounds, or that it contains a higher fraction of crystalline ice than previously though. Or, in keeping with the recent impact of a possible cometary object with Jupiter, if the Haumea's spot is a scar of a recent impact then the spot material might resemble the composition of the impactor, perhaps mixed with material from the inner layers of Haumea.

Further observations of this spot are planned for early 2010 using the ESO Very Large Telescope. “Now we will get detailed spectroscopy of the spot to hopefully identify its chemical composition and solve the puzzle of its origin,” says Lacerda.

The Planets
From tiny Mercury to distant Neptune and Pluto, The Planets profiles each of the Solar System's members in depth, featuring the latest imagery from space missions. The tallest mountains, the deepest canyons, the strongest winds, raging atmospheric storms, terrain studded with craters and vast worlds of ice are just some of the sights you'll see on this 100-page tour of the planets.
 GET YOUR COPY

Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.
 GET YOUR COPY

3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!
 GET YOUR COPY


HOME | NEWS ARCHIVE | MAGAZINE | SOLAR SYSTEM | SKY CHART | RESOURCES | STORE | SPACEFLIGHT NOW

© 2014 Pole Star Publications Ltd.