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
NASA delays launch of Mars InSight lander
Posted: Thu, Dec 24 6:12 PM ET (2312 GMT)

Falcon 9 launches ORBCOMM satellites and lands first stage
Posted: Thu, Dec 24 6:03 PM ET (2303 GMT)

NASA astronauts complete brief ISS repair spacewalk
Posted: Thu, Dec 24 5:55 PM ET (2255 GMT)

news links
Monday, February 8
Filling in the details
The Space Review — 2:42 pm ET (1942 GMT)
Rethinking the national security space strategy: part 3
The Space Review — 2:39 pm ET (1939 GMT)
Preserving our space heritage
The Space Review — 2:39 pm ET (1939 GMT)
Review: SpaceX’s Dragon
The Space Review — 2:37 pm ET (1937 GMT)


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