f********2
发帖数: 368 | 1 在2005年5月，美国宇航局宣布航海家一號已經在2004年12月，在距離太陽94天文單位
的地方越過終端震波進入日鞘中
2010年12月，旅行者1号已经感受不到太阳风了。
33年的太阳风和行星引力加速，旅行者1号目前是还在工作的速度最快的人造飞行器。
December 13, 2010
PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has
reached a distant point at the edge of our solar system where there is no
outward motion of solar wind.
Now hurtling toward interstellar space some 17.4 billion kilometers (10.8
billion miles) from the sun, Voyager 1 has crossed into an area where the
velocity of the hot ionized gas, or plasma, emanating directly outward from
the sun has slowed to zero. Scientists suspect the solar wind has been
turned sideways by the pressure from the interstellar wind in the region
between stars.
The event is a major milestone in Voyager 1's passage through the
heliosheath, the turbulent outer shell of the sun's sphere of influence, and
the spacecraft's upcoming departure from our solar system.
"The solar wind has turned the corner," said Ed Stone, Voyager project
scientist based at the California Institute of Technology in Pasadena, Calif
. "Voyager 1 is getting close to interstellar space."
Our sun gives off a stream of charged particles that form a bubble known as
the heliosphere around our solar system. The solar wind travels at
supersonic speed until it crosses a shockwave called the termination shock.
At this point, the solar wind dramatically slows down and heats up in the
heliosheath.
Launched on Sept. 5, 1977, Voyager 1 crossed the termination shock in
December 2004 into the heliosheath. Scientists have used data from Voyager 1
's Low-Energy Charged Particle Instrument to deduce the solar wind's
velocity. When the speed of the charged particles hitting the outward face
of Voyager 1 matched the spacecraft's speed, researchers knew that the net
outward speed of the solar wind was zero. This occurred in June, when
Voyager 1 was about 17 billion kilometers (10.6 billion miles) from the sun.
Because the velocities can fluctuate, scientists watched four more monthly
readings before they were convinced the solar wind's outward speed actually
had slowed to zero. Analysis of the data shows the velocity of the solar
wind has steadily slowed at a rate of about 20 kilometers per second each
year (45,000 mph each year) since August 2007, when the solar wind was
speeding outward at about 60 kilometers per second (130,000 mph). The
outward speed has remained at zero since June.
The results were presented today at the American Geophysical Union meeting
in San Francisco.
"When I realized that we were getting solid zeroes, I was amazed," said Rob
Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and
senior staff scientist at the Johns Hopkins University Applied Physics
Laboratory in Laurel, Md. "Here was Voyager, a spacecraft that has been a
workhorse for 33 years, showing us something completely new again."
Scientists believe Voyager 1 has not crossed the heliosheath into
interstellar space. Crossing into interstellar space would mean a sudden
drop in the density of hot particles and an increase in the density of cold
particles. Scientists are putting the data into their models of the
heliosphere's structure and should be able to better estimate when Voyager 1
will reach interstellar space. Researchers currently estimate Voyager 1
will cross that frontier in about four years.
"In science, there is nothing like a reality check to shake things up, and
Voyager 1 provided that with hard facts," said Tom Krimigis, principal
investigator on the Low-Energy Charged Particle Instrument, who is based at
the Applied Physics Laboratory and the Academy of Athens, Greece. "Once
again, we face the predicament of redoing our models."
A sister spacecraft, Voyager 2, was launched in Aug. 20, 1977 and has
reached a position 14.2 billion kilometers (8.8 billion miles) from the sun.
Both spacecraft have been traveling along different trajectories and at
different speeds. Voyager 1 is traveling faster, at a speed of about 17
kilometers per second (38,000 mph), compared to Voyager 2's velocity of 15
kilometers per second (35,000 mph). In the next few years, scientists expect
Voyager 2 to encounter the same kind of phenomenon as Voyager 1.
The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena,
Calif., which continues to operate both spacecraft. For more information
about the Voyager spacecraft, visit: http://www.nasa.gov/voyager . JPL is a division of the California Institute of Technology in Pasadena. | f********2
发帖数: 368 | 2 速度是17.2 (kilometers / second) = 38 475.3042 mph
也是太阳系里离太阳最遥远的人造/自然物体 | c**c
发帖数: 2593 | 3 嗯，2004年底Asimovs杂志发表Gregory Benford的小说
Hydrogen Wall，大概就是为了呼应这两个飞行器穿越太
阳系氢墙的历史性事件，呵呵。
【在 f********2 的大作中提到】
: 在2005年5月，美国宇航局宣布航海家一號已經在2004年12月，在距離太陽94天文單位
: 的地方越過終端震波進入日鞘中
: 2010年12月，旅行者1号已经感受不到太阳风了。
: 33年的太阳风和行星引力加速，旅行者1号目前是还在工作的速度最快的人造飞行器。
: December 13, 2010
: PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has
: reached a distant point at the edge of our solar system where there is no
: outward motion of solar wind.
: Now hurtling toward interstellar space some 17.4 billion kilometers (10.8
: billion miles) from the sun, Voyager 1 has crossed into an area where the
| f********2
发帖数: 368 | 4 大牛你好 嘿嘿
hydrogen wall是一篇相当震撼的小说啊
不过其实那个时候对太阳圈顶的估计还不准确
直到2010年12月接收到旅行者1号太阳风读数始终为0，才算是一个直接证据
不过也有可能是那个探测器坏掉了，谁知道呢，都那么多年了
【在 c**c 的大作中提到】
: 嗯，2004年底Asimovs杂志发表Gregory Benford的小说
: Hydrogen Wall，大概就是为了呼应这两个飞行器穿越太
: 阳系氢墙的历史性事件，呵呵。
| c**c
发帖数: 2593 | 5 呵呵，回头详细看了一下，发现我们前面用词都有点混淆。
我说的氢墙是个笼统的称谓，指的是太阳风与星际风碰撞
交战的大体区域。这里有个比较详细的介绍（可以点那些
图片看大图）：
http://en.wikipedia.org/wiki/Hydrogen_wall
这个区域，从内往外其实还有几层界面，第一层叫
Termination Shock，是太阳风粒子从超音速降到亚音速
的激波所在地。第二层叫Heliopause，是太阳风粒子减速
到相对静止，开始跟星际介质混同的地方。第三层叫做
Bow Shock，是太阳带着Heliopause在银河系中运动，推
动紧挨着的星际介质，挤压更远地方的星际介质的区域。
2004年底旅行者1号穿越的是第一层Termination Shock。
这回新闻里说的是它穿越了第二层Heliopause。接下去
如果这东东机器还能正常工作若干年，也许还能成功穿
越Bow Shock。
有趣的是，旅行者1号在2004年离太阳94个天文单位时穿
越Termination Shock，而旅行者2号在2006年离太阳76个
天文单位时穿越Termination Shock。这也许意味着太阳
系氢墙是个北凸南凹的不规则形状。也许是因为这些年太
阳所在的银河系这片区域，出于某些原因，正好有从南往
北吹的星际风。。。
【在 f********2 的大作中提到】
: 大牛你好 嘿嘿
: hydrogen wall是一篇相当震撼的小说啊
: 不过其实那个时候对太阳圈顶的估计还不准确
: 直到2010年12月接收到旅行者1号太阳风读数始终为0，才算是一个直接证据
: 不过也有可能是那个探测器坏掉了，谁知道呢，都那么多年了
| f********2
发帖数: 368 | 6 谢谢 学习了
【在 c**c 的大作中提到】
: 呵呵，回头详细看了一下，发现我们前面用词都有点混淆。
: 我说的氢墙是个笼统的称谓，指的是太阳风与星际风碰撞
: 交战的大体区域。这里有个比较详细的介绍（可以点那些
: 图片看大图）：
: http://en.wikipedia.org/wiki/Hydrogen_wall
: 这个区域，从内往外其实还有几层界面，第一层叫
: Termination Shock，是太阳风粒子从超音速降到亚音速
: 的激波所在地。第二层叫Heliopause，是太阳风粒子减速
: 到相对静止，开始跟星际介质混同的地方。第三层叫做
: Bow Shock，是太阳带着Heliopause在银河系中运动，推
| t*n
发帖数: 14458 | 7 会不会把三体人招来
在2005年5月，美国宇航局宣布航海家一號已經在2004年12月，在距離太陽94天文單位
的地方越過終端震波進入日鞘中
2010年12月，旅行者1号已经感受不到太阳风了。
33年的太阳风和行星引力加速，旅行者1号目前是还在工作的速度最快的人造飞行器。
December 13, 2010
PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has
reached a distant point at the edge of our solar system where there is no
outward motion of solar wind.
Now hurtling toward interstellar space some 17.4 billion kilometers (10.8
billion miles) from the sun, Voyager 1 has crossed into an area where the
velocity of the hot ionized gas, or plasma, emanating directly outward from
the sun has slowed to zero. Scientists suspect the solar wind has been
turned sideways by the pressure from the interstellar wind in the region
between stars.
The event is a major milestone in Voyager 1's passage through the
heliosheath, the turbulent outer shell of the sun's sphere of influence, and
the spacecraft's upcoming departure from our solar system.
"The solar wind has turned the corner," said Ed Stone, Voyager project
scientist based at the California Institute of Technology in Pasadena, Calif
. "Voyager 1 is getting close to interstellar space."
Our sun gives off a stream of charged particles that form a bubble known as
the heliosphere around our solar system. The solar wind travels at
supersonic speed until it crosses a shockwave called the termination shock.
At this point, the solar wind dramatically slows down and heats up in the
heliosheath.
Launched on Sept. 5, 1977, Voyager 1 crossed the termination shock in
December 2004 into the heliosheath. Scientists have used data from Voyager 1
's Low-Energy Charged Particle Instrument to deduce the solar wind's
velocity. When the speed of the charged particles hitting the outward face
of Voyager 1 matched the spacecraft's speed, researchers knew that the net
outward speed of the solar wind was zero. This occurred in June, when
Voyager 1 was about 17 billion kilometers (10.6 billion miles) from the sun.
Because the velocities can fluctuate, scientists watched four more monthly
readings before they were convinced the solar wind's outward speed actually
had slowed to zero. Analysis of the data shows the velocity of the solar
wind has steadily slowed at a rate of about 20 kilometers per second each
year (45,000 mph each year) since August 2007, when the solar wind was
speeding outward at about 60 kilometers per second (130,000 mph). The
outward speed has remained at zero since June.
The results were presented today at the American Geophysical Union meeting
in San Francisco.
"When I realized that we were getting solid zeroes, I was amazed," said Rob
Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator and
senior staff scientist at the Johns Hopkins University Applied Physics
Laboratory in Laurel, Md. "Here was Voyager, a spacecraft that has been a
workhorse for 33 years, showing us something completely new again."
Scientists believe Voyager 1 has not crossed the heliosheath into
interstellar space. Crossing into interstellar space would mean a sudden
drop in the density of hot particles and an increase in the density of cold
particles. Scientists are putting the data into their models of the
heliosphere's structure and should be able to better estimate when Voyager 1
will reach interstellar space. Researchers currently estimate Voyager 1
will cross that frontier in about four years.
"In science, there is nothing like a reality check to shake things up, and
Voyager 1 provided that with hard facts," said Tom Krimigis, principal
investigator on the Low-Energy Charged Particle Instrument, who is based at
the Applied Physics Laboratory and the Academy of Athens, Greece. "Once
again, we face the predicament of redoing our models."
A sister spacecraft, Voyager 2, was launched in Aug. 20, 1977 and has
reached a position 14.2 billion kilometers (8.8 billion miles) from the sun.
Both spacecraft have been traveling along different trajectories and at
different speeds. Voyager 1 is traveling faster, at a speed of about 17
kilometers per second (38,000 mph), compared to Voyager 2's velocity of 15
kilometers per second (35,000 mph). In the next few years, scientists expect
Voyager 2 to encounter the same kind of phenomenon as Voyager 1.
The Voyagers were built by NASA's Jet Propulsion Laboratory in Pasadena,
Calif., which continues to operate both spacecraft. For more information
about the Voyager spacecraft, visit: http://www.nasa.gov/voyager . JPL is a division of the California Institute of Technology in Pasadena.
【在 f********2 的大作中提到】
: 在2005年5月，美国宇航局宣布航海家一號已經在2004年12月，在距離太陽94天文單位
: 的地方越過終端震波進入日鞘中
: 2010年12月，旅行者1号已经感受不到太阳风了。
: 33年的太阳风和行星引力加速，旅行者1号目前是还在工作的速度最快的人造飞行器。
: December 13, 2010
: PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has
: reached a distant point at the edge of our solar system where there is no
: outward motion of solar wind.
: Now hurtling toward interstellar space some 17.4 billion kilometers (10.8
: billion miles) from the sun, Voyager 1 has crossed into an area where the
| s***i
发帖数: 600 | 8 不会。
三体人还不能探测 4 ly 以外缓慢加速，缓慢飞行的 微小飞行器。
人类还没有恒星级的广播能力。
has
no
(10.8
【在 t*n 的大作中提到】
: 会不会把三体人招来
:
: 在2005年5月，美国宇航局宣布航海家一號已經在2004年12月，在距離太陽94天文單位
: 的地方越過終端震波進入日鞘中
: 2010年12月，旅行者1号已经感受不到太阳风了。
: 33年的太阳风和行星引力加速，旅行者1号目前是还在工作的速度最快的人造飞行器。
: December 13, 2010
: PASADENA, Calif. – The 33-year odyssey of NASA's Voyager 1 spacecraft has
: reached a distant point at the edge of our solar system where there is no
: outward motion of solar wind.
|
|
