Astronomy Now Home
Home Magazine Sky Chart Resources Store

On Sale Now!



The September 2014 issue of Astronomy Now is on sale! Order direct from our store (free 1st class post & to UK addresses). The Astronomy Now iPad/iPhone editions are now available worldwide on the 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








Moon used to investigate sub-atomic particles
by Jim Allen
for ASTRONOMY NOW
Posted: 06 December 2010


Bookmark and Share

Astronomers from the University of Iowa and the Naval Research Laboratory have used the Moon to eliminate a number of causes for ultra-high energy neutrinos.

Neutrinos are chargeless, massless particles found throughout the Universe. Due to their non-interacting nature they are very difficult to detect, with billions passing through you every second. In the past scientists have devised a number of imaginative detection methods, often involving filling large underground caverns with heavy or pure water and waiting for sporadic emissions of radiation. Now a group of scientists are using the Moon to aid in detecting very high energy neutrinos.


An impression of the VLA observing the lunar neutrino emissions. Image: Ted Jaeger, University of Iowa, NRAO/AUI/NSF.

Using the Very Large Array (VLA) radio telescope and the Extended Very Large Array (EVLA) Ted Jaeger of the University of Iowa and the Naval Research Laboratory and Robert Mutel and Kenneth Gayley of the University of Iowa searched for neutrinos interacting with the Moon. Although it is not possible to detect neutrinos directly using a radio telescope, it is possible to detect the radio waves produced by the interaction of neutrinos with the Moon. It was these emissions that the team was trying to detect.

After satisfying themselves that the experiment was working correctly by launching a helium balloon transmitter above the VLA, the detectors were then turned towards the lunar edge. Taking measurements for 200 hours the group report in the December issue of Astroparticle Physics that they had not detected any ultra-high energy neutrino signals.

This technique has been used since 1995, but this was the first time that measurements of this sensitivity have been recorded. Theoretical predictions of the source of the high energy neutrinos range between black holes at the centre of distant galaxies to exploding stars and even tears in the fabric of space-time. Due to the absence of any emissions some of these sources can now be ruled out.

“Our observations have set a new upper limit – the lowest yet – for the amount of the type of neutrinos we sought,” Mutel said. “This limit eliminates some models that proposed bursts of these neutrinos coming from the halo of the Milky Way Galaxy”.

In order to test other predictions more sensitive measurements will need to be taken. According to Mutel, “when we develop the ability to detect these particles, we will open a new window for observing the Universe and advancing our understanding of basic astrophysics”.

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.