[ti:Telescope on Moon Could Study Oldest Stars in Universe]
[by:www.21voa.com]
[00:00.00]更多听力请访问21VOA.COM
[00:00.04]American astronomers say new evidence supports the idea
[00:05.84]that a large telescope on the moon
[00:09.28]could study the oldest stars in the universe.
[00:14.92]A group of international scientists
[00:18.20]proposed the idea to build such a telescope to NASA in 2008.
[00:26.24]The U.S. space agency looked into the plan,
[00:29.56]but later decided against it.
[00:33.20]NASA said not enough supporting science
[00:36.68]on the earliest stars existed at the time.
[00:42.00]Now, a group of astronomers at the University of Texas at Austin
[00:48.16]say they have found new evidence that a telescope on the moon
[00:54.08]would be able to gather data on the first stars in the universe.
[01:01.04]The team, led by NASA Hubble Fellow Anna Schauer,
[01:06.12]is set to publish their research results
[01:09.48]in an upcoming issue of The Astrophysical Journal.
[01:15.28]The researchers named the device Ultimately Large Telescope.
[01:21.72]It would operate with a 100-meter mirror made out of liquid.
[01:28.32]It could receive power from a solar power collection station
[01:33.32]on the moon and send data to a satellite in lunar orbit.
[01:39.96]A mirror made of liquid is lighter than a glass one
[01:44.28]and less costly to transport to the moon.
[01:49.04]The astronomers say the liquid
[01:51.64]would include metallic material for effective reflection.
[01:57.48]The team is proposing that the telescope
[02:01.04]could be placed inside a crater at the moon's north or south pole.
[02:07.84]The device would study the first stars
[02:11.00]by centering on the same area of sky continuously,
[02:16.08]in an effort "to collect as much light from them as possible,"
[02:21.60]the scientists said in a statement.
[02:25.76]The first stars in the universe
[02:28.72]are believed to have formed more than 13 billion years ago.
[02:34.40]The stars are thought to have formed after the Big Bang
[02:39.08]– the large explosion that many scientists believe created the universe.
[02:45.64]The team says these stars
[02:48.48]were born out of a mix of hydrogen and helium gas.
[02:54.48]They are likely 10 to 100 times larger than our sun.
[03:00.68]Volker Bromm is a professor at the University of Texas at Austin
[03:06.60]and a leader of the project.
[03:10.60]"We live in a universe of stars," he said in a statement.
[03:15.60]But an important remaining question
[03:19.12]is "how star formation got going early in cosmic history," he added.
[03:26.84]The scientists say their moon-based observer
[03:30.76]would be able to gather data on the oldest stars,
[03:34.88]which no other telescope is equipped to do.
[03:39.24]NASA has plans to send the James Webb Space Telescope,
[03:44.68]its newest telescope, to space in October 2021.
[03:51.20]The launch of the James Webb has been delayed many times.
[03:57.12]NASA says the telescope is designed
[04:00.32]to look deeper into space and offer more answers about the past
[04:05.76]than any other spacecraft.
[04:08.48]It is a large infrared telescope,
[04:11.68]with a nearly seven-meter mirror for exploring space.
[04:17.28]Bromm said that throughout the history of astronomy,
[04:21.68]telescopes have become more and more powerful,
[04:25.84]permitting exploration of times closer to the Big Bang.
[04:31.88]He added that the James Webb Space Telescope
[04:35.68]is expected to reach the time when galaxies first formed.
[04:41.68]"But theory predicts that there was an even earlier time,
[04:46.16]when galaxies did not yet exist,
[04:49.28]but where individual stars first formed," Bromm said.
[04:55.12]"This moment of 'very first light' is beyond the capabilities
[05:00.80]even of the powerful (James Webb),
[05:03.68]and instead needs an ‘ultimate' telescope."
[05:08.24]The team is proposing that the world astronomy community
[05:13.84]revisit the plan to use a lunar liquid-mirror telescope
[05:19.72]as a way to directly observe these early stars for the first time.
[05:26.48]I'm Bryan Lynn. 更多听力请访问21VOA.COM
END OF TRACK. "END OF TRACK." The two men bowed. "Whoever was that person you were talking to?" she enquired, as soon as they stood together. The took of triumph faded from her eyes, she had grown worn and weary. The roses were wilting on the walls, the lights were mostly down now. Hetty, looking in to see if anything was wanted, found herself driven away almost fiercely. I only saw Master Jervie once when he called at tea time, The year 1747 was opened by measures of restriction. The House of Lords, offended at the publication of the proceedings of the trial of Lord Lovat, summoned the parties to their bar, committed them to prison, and refused to liberate them till they had pledged themselves not to repeat the offence, and had paid very heavy fees. The consequence of this was that the transactions of the Peers were almost entirely suppressed for nearly thirty years from this time, and we draw our knowledge of them chiefly from notes taken by Horace Walpole and Lord Chancellor Hardwicke. What is still more remarkable, the reports of the House of Commons, being taken by stealth, and on the merest sufferance, are of the most meagre kind, sometimes altogether wanting, and the speeches are given uniformly under fictitious names; for to have attributed to Pitt or Pelham their[112] speeches by name would have brought down on the printers the summary vengeance of the House. Many of the members complained bitterly of this breach of the privileges of Parliament, and of "being put into print by low fellows"; but Pelham had the sense to tolerate them, saying, "Let them alone; they make better speeches for us than we can make for ourselves." Altogether, the House of Commons exhibited the most deplorable aspect that can be conceived. The Ministry had pursued Walpole's system of buying up opponents by place, or pension, or secret service money, till there was no life left in the House. Ministers passed their measures without troubling themselves to say much in their behalf; and the opposition dwindled to Sir John Hinde Cotton, now dismissed from office, and a feeble remnant of Jacobites raised but miserable resistance. In vain the Prince of Wales and the secret instigations of Bolingbroke and Doddington stimulated the spirit of discontent; both Houses had degenerated into most silent and insignificant arenas of very commonplace business. "It certainly will be. Miss Widgeon," answered Maria, with strictly "company manners." "One who has never had a brother exposed to the constant dangers of army life can hardly understand how glad we all feel to have Si snatched from the very jaws of death and brung back to us." "Just plug at 'em as you would at a crow, and then go on your way whistlin'?" persisted Harry. "Hurroo!" echoed Hennessey; "that's the ticket." "Come forward, keeper," continued the baron, "and state how these arrows came into your hands!" "Yes." HoMEJULIA京香2018下载
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