spacetoday.net: space news from around the webin association with SpaceNews


Chandra measures Hubble constant
Posted: Wed, Aug 9, 2006, 8:55 AM ET (1255 GMT)
Astronomers have used data from NASA's Chandra X-Ray Observatory to make an independent measure of the Hubble constant, a key metric of the expansion of the universe. The astronomers used x-ray observations of 38 galaxy clusters, coupled with separate radio observations, to measure the distances of the clusters, the most distant of which were 9.3 billion light-years away. Those distances, combined with previous measurements of the speeds at which the clusters are receding, allowed astronomers to calculate the Hubble constant. Their result, 77 kilometers per second per megaparsec (plus or minus 15 percent) is within the margin of error previous independent calculations of the constant, 72 km/sec/Mpc, using the Hubble Space Telescope. The Hubble constant is one of the key values in cosmology, telling astronomers the rate at which the universe is expanding; the result confirms earlier estimates that the universe is between 12 and 14 billion years old.
<<previous article   next article>>
news in brief
Space Force adds Rocket Lab and Stoke Space to NSSL contract
Posted: Sun, Mar 30 9:19 AM ET (1319 GMT)

Cygnus departs from ISS
Posted: Sun, Mar 30 9:14 AM ET (1314 GMT)

Vulcan Centaur certified for national security launches
Posted: Sun, Mar 30 9:10 AM ET (1310 GMT)

news links
Thursday, April 3
How a kid from Pemberton helped lead a landmark commercial Moon landing
Australian Broadcasting Corporation — 6:00 am ET (1000 GMT)
Eutelsat Begins OneWeb Services for the Aviation Market
ViaSatellite — 5:59 am ET (0959 GMT)
Debrief: Vulcan On Deck
Aviation Week — 5:56 am ET (0956 GMT)


about spacetoday.net   ·   info@spacetoday.net   ·   mailing list