本帖最后由 suhuasky 于 2009-7-27 12:37 编辑
http://www.nbd.com.cn/newshtml/20090722/20090722194654993.html
木星又被撞 星表疤痕可装地球（组图）
http://www.nbd.com.cn 2009-07-22 19:46:54 来源: NBD综合 核心提示：美国国家航空航天局21日证实，木星在过去相当短一段时间内再次遭遇其他星体撞击，使木星南极附近落下黑色疤斑，撞击处上空的木星大气层出现一个地球大小的空洞。
法新社称，澳大利亚一位业余天文学家上周四最先发现这个凹痕。美国太空总署其后以红外线望远镜，拍摄到木星南端的大气层有一个凹痕。
一位民间科学家于7月19日首次报告说，一颗巨大的天体曾与木星碰撞在一起，并且留下了一个明显的黑斑。这一发现是有记录可查的科学家第二次在一颗巨行星的大气中瞥见了一个碰撞的疤痕。美国加利福尼亚州帕萨迪纳市美国宇航局（NASA）喷气推进实验室（JPL）的博士后、天文学家Leigh Fletcher表示：“我从没指望我能够发现类似的东西。”
当地时间晚上11点30分左右，家住澳大利亚Murrumbateman的业余天文爱好者Anthony Wesley按照惯例，用他的37厘米口径的望远镜——专业水平一般为1000厘米口径的望远镜——对木星实施观测。然而此时他发现了一些不同寻常的迹象：在木星南极区域的上空，出现了一个直径为几千公里的绕轴的黑斑（如图）。Wesley本来打算要结束这次观测，并且他最初认为这个短暂的黑斑不过是一个典型的黑色极地风暴。但他最终决定还是再继续观测一会儿，15分钟之后，Wesley相信他所观测到的是一个完全不同的东西。
Wesley怀疑这个黑斑是一次撞击造成的结果，并迅速与Fletcher以及JPL的天文学家Glenn Orton取得了联系。幸运的是，两位研究人员之前曾预定了NASA位于夏威夷的红外天文望远镜的使用时间（从JPL进行远程操控），因此他们有机会进行了近距离观测。研究人员发现了与众不同的红外信号，这些信号与Orton和其他人在15年前的这一周发现的信号类似——当时苏梅克-列维九号彗星破裂为21个碎块，并接连与木星相撞。Fletcher表示：“我们无法想象会如此幸运，有一名杰出的民间科学家能够在几个小时之内报告了这一发现。”Orton补充说，这样的民间科学家“正在进行着一些有关木星上发生了什么的基础性观测工作”。
曾利用哈勃空间望远镜对1994年的木彗碰撞进行观测的美国科罗拉多州博尔德市空间科学研究所的天文学家Heidi Hammel认为，这次撞击“多少有些让人感到惊讶”。他说：“我们都认为这是一个概率极低的事件。”Hammel认为，这一迄今为止罕见的事件看起来像是一起类似于苏梅克-列维九号彗星的中等级别的撞击。然而马里兰州劳雷尔市约翰·霍普金斯大学应用物理实验室的天文学家Harold Weaver则表示，撞击木星的岩石小行星或冰体彗星的大小很难被估算。有关苏梅克-列维九号彗星的大小，科学家从未达成过一致意见，但是这颗天体的直径或许为几百米——至多1000米，并且以每小时几万千米的速度运行。
如果科学家想要得到有关这次木星撞击事件的任何新信息，那么他们必须得快一点儿了。在天文学家加速递交他们有关紧急事件的天文望远镜——包括最近刚刚修好的哈勃空间望远镜——使用时间申请的这一刻，木星上的大风正在将这个黑斑吹散。
科学家估计，这个凹痕是由彗星碎片或冰块撞击造成。不过天文学家们表示，要想彻底查清该痕迹成因，必须对木星进行持续系统地观测。
木星是太阳系最大的行星，体积比地球大11倍。目前，全世界范围内已有越来越多的天文爱好者加入到对天空的观测活动之中。就在不久前，美国纽约的一名中学生还曾发现了一颗并不明亮的超新星(目前已被命名为SN 2008ha)。
（本文来源：科学网 新华网 中国新闻网）
7月26日：
照片：
Image captured by Anthony Wesley on 19th July 2009 at 1554UTC from Murrumbateman Australia
I've been slashdotted, and my web server crushed. Now moved this to jupiter.samba.org provided by Tridge - thanks mate, you saved my a$$, you're a legend. Preliminary image showing a black mark in Jupiters South Polar Region (SPR) which is almost certainly the result of a large impact - either an asteroid or comet - similar to the Shoemaker-Ley impacts in 1994. Note to Media Images from this page may be used for editorial use only in news stories and publications provided correct attribution is retained.
Date and Time of Report Dark impact mark first noted at approximately 1330UTC on 19th July 2009 from my home observatory just outside Murrumbateman NSW Australia. Inspection of earlier images shows the impact visible on the planets limb at 1401UTC. Equipment and Contact Details
Contact info: Anthony Wesley awesley@smartnetworks.com.au awesley@acquerra.com.au http://www.acquerra.com.au/astro Picture of Anthony and his 14.5 inch scopeScope: Homebrew GEM mounted Newtonian using a 14.5" Royce conical mirror (link to images removed until the slashdot tsumani retreats)Mount: Losmandy TitanOptics: - 14.5" f/5 Royce conical primary - 1/30 wave Antares Optics secondary - Televue 5x powermate , working at 7.7xCamera: Point Grey Research Dragonfly2 mono camera, ICX424alFilters: Astrodon I-Series RGBCapture details: 60 seconds in each filter @ 47fps.Capture software: Coriander Operating System: Linux (Fedora 10 x86)Processing software: Ninox for crop and presort Registax for alignment and stacking Astra Image for deconvolution and RGB align The Gimp for cleanup and captioning.Observation Report
Update (20th July 1100UT) Glenn Orton from JPL has imaged this site using the NASA Infrared Telescope on Hawaii and confirms that it is an impact site and not a localised weather event. I started this imaging session on Jupiter at approximately 11pm local time (1300UTC). The weather prediction was not promising, clear skies but a strong jetstream overhead according to the Bureau of Met. The temperature was also unusually high for this time of year (winter), also a bad sign. The scope in use was my new 14.5" newtonian, in use now for a few weeks and so far returning excellent images. I was pleasantly surprised to find reasonable imaging conditions and so I decided to continue recording data until maybe 1am local time. By about midnight (12:10 am) the seeing had deteriorated and I was ready to quit. Indeed I had hovered the mouse over the exit button on my capture application (Coriander for Linux) and then changed my mind and decided instead to simply take a break for 30 minutes and then check back to see if the conditions had improved. It was a very near thing. When I came back to the scope at about 12:40am I noticed a dark spot rotating into view in Jupiters south polar region started to get curious. When first seen close to the limb (and in poor conditions) it was only a vaguely dark spot, I thouht likely to be just a normal dark polar storm. However as it rotated further into view, and the conditions improved I suddenly realised that it wasn't just dark, it was black in all channels, meaning it was truly a black spot. My next thought was that it must be either a dark moon (like Callisto) or a moon shadow, but it was in the wrong place and the wrong size. Also I'd noticed it was moving too slow to be a moon or shadow. As far as I could see it was rotating in sync with a nearby white oval storm that I was very familiar with - this could only mean that the back feature was at the cloud level and not a projected shadow from a moon. I started to get excited. It took another 15 minutes to really believe that I was seeing something new - I'd imaged that exact region only 2 days earlier and checking back to that image showed no sign of any anomalous black spot. Now I was caught between a rock and a hard place - I wanted to keep imaging but also I was aware of the importance of alerting others to this possible new event. Could it actually be an impact mark on Jupiter? I had no real idea, and the odds on that happening were so small as to be laughable, but I was really struggling to see any other possibility given the location of the mark. If it really was an impact mark then I had to start telling people, and quickly. In the end I imaged for another 30 minutes only because the conditions were slowly improving and each capture was giving a slightly better image than the last. Eventually I stopped imaging and went up to the house to start emailing people, with this image above processed as quick and dirty as possible just to have something to show. More images will come along from me and many other people in the next few days. *NOTE* Priority is being given to processing and uploading images as fast as possible, so the image quality is no necessarily as good as it might be. When time permits these images will be replaced by higher quality versions. Anthony
This is a very early image showing the impact mark (top right, on the limb). This image is red channel data only.
It is possible that this is the earliest recorded image of the event. p.s. The GRS looks nice too, this was my real target for imaging this night!
Another very early image of the dark spot, red channel data only. It's just visible on the limb to the upper right. Of course, it wasn't visible to me at the time I was recording the data, and after this sequence was captured I took a 30 minute break away from the scope... When I came back I noticed the dark spot.
Note the time on this image was incorrectly labelled as 141134UTC, this has been corrected
Closeup of this region in green light only, from reprocessed data (155537UTC). 3 small dark spots can be seen. Update: Two of these three small spots may be pre-existing small storms. Thanks to a blink comparison by Brett Hughes.
Same closeup as previous (155537UTC) , now in colour. 3 small dark spots can be seen in addition to the main one, possibly more. Still looking for better quality raw data from other imaging runs around this time. Update: Two of these three small spots may be pre-existing small storms. Thanks to a blink comparison by Brett Hughes.
Earlier image showing the impact zone in slightly better seeing, but unfortunately the site itself is not as well resolved due to the viewing angle.
A later image in reasonable seeing.
One of the last images from this session, this image has been more carefully processed to avoid artifacts by using 3x upsampling on the data before alignment and stacking
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
重量级武器上场：
哈勃空间望远镜：
July 24, 2009: NASA scientists have interrupted the checkout and calibration of the Hubble Space Telescope to aim the recently refurbished observatory at a new expanding spot on the giant planet Jupiter. The spot, caused by the impact of a comet or an asteroid, is changing day to day in the planet's cloud tops. The Hubble picture, taken on July 23, is the sharpest visible-light picture taken of the impact feature. The observations were made with Hubble's new camera, the Wide Field Camera 3 (WFC3). WFC3 is not yet fully calibrated, and while it is possible to obtain celestial images, the camera's full power cannot yet be realized for most observations. The WFC3 can still return meaningful science images that will complement the Jupiter pictures being taken with ground-based telescopes.
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
7月27日更新：
| Backyard observatory, Watauga, Texas, USA |
| It is stunning to see what can be done with equipment available to amateur astronomers. This morning I was fortunate to have very favorable conditions for imaging, and captured a truly once in a lifetime image of Jupiter, complete with the recently formed impact debris cloud, using my LX90 8" telescope! An element of luck certainly was also a factor, since I knew there was a 50/50 chance the impact debris would be facing Earth while Jupiter was visible during the window of opportunity for imaging this morning. Although Jupiter did not rise above the trees until 02:59a.m. local time, any hint of sleepiness dissapated once the image of this special event painted itself on the screen of the computer! Photo details: Philips PCVC740K camera, Meade 8" LX90 telescope, Meade IR filter. 329 of 621 1/33sec exposures stacked and processed in Registax Software. |
| Central Coast, NSW Australia |
| Hi Tony After breaking the news of Anthony Wesley’s discovery of an impact scar on Jupiter on Monday morning (while I was waiting to board a plane to Melbourne), Friday night was my first opportunity to capture an image of the now famous "Wesley Impact Scar", or "Bird Strike" (Anthony’s forum name is "bird"). I’d been in Melbourne all week and was very frustrated to have not been able to capture an image of it until now. On Friday night, 24th July, the impact scar was transitting while Jupiter was almost right overhead, but unfortunately the seeing conditions were only average, and deteriorated even further as the Bird Strike came more into view. Hopefully I'll get another opportunity this week, with any luck, in better seeing. More here: http://www.mikesalway.com.au/200 ... pact-scar-24th-july Thanks for looking. |
| Jupiter impact about 5:00 am EDT 7-23-09. Photo taken with a TEC 200 at F-32 in poor seeing with SkyNyx color camera. |
| Chesterfield, Missouri, USA |
| The impact site was readily visible on the monitor at 30 fps in the live video stream using a DBK21AF04.AS color camera on a 12-inch Newtonian telescope with eyepiece projection at f/42. |
| Jupiter with dark spot (near ir + RGB). Intes MK67 + Meade barlow 2x apo Camera: Magzero MZ5m (IRpass) + Toucam Pro (RGB). Clear Sky. |
| I was really suprised how easy the spot was visible. I did make observations with a 20cm newton and the spot was visible properly on the screen! |
| Impact area at Jupiter Video with frames stacked on Registax. |
| Hartmann Creek State Park near Waupaca, WI |
This was first light for the new Celestron NexImage webcam at WOW (Wisconsin Observer’s Weekend), a star party held each year at Hartmann Creek Campgrounds/Waupaca Wisconsin and sponsored by NewStar (Northeastern Wisconsin Observers). We were very anxious to try out the camera and the new impact mark on Jupiter proved to be a perfect opportunity to see what it could do. The seeing was average, but the night was clear as we went to work on imaging the impact area immediately as Jupiter cleared the tree line to the South. The images were captured July 24 2009 04:41UT to 05:51 UT bracketing the transit of the impact spot. Nine consecutive images were processed in RegiStax4 and then assembled with Photoshop and ImageReady into a time lapse animation. As an added bonus, during this transit of the new dark spot this evening, it was also visible during moments of good seeing in telescopes on the field as small as 10” diameter. Telescopes as large as 20” diameter were also available to observe the night sky wonders from WOW. 12” Meade LX200, 2X Barlow, Celestron NexImage webcam at an effective 6000 mm f.l. at f20, capture series taken in one minute intervals at 1/50th sec. Images were captured with AmCap, stacked and processed in Registax4, and layered and animated in Photoshop and ImageReady. Animation courtesy of Anthony Kroes & Tom Jorgenson
|
| | What's up in Space | July 27, 2009 | | | JUPITER'S IMPACT CLOUD EXPANDS: Jupiter's impact cloud is expanding. On July 19th, when it was discovered by amateur astronomer Anthony Wesley, the dark mark near Jupiter's south pole was barely visible in backyard telescopes. Five days later Wesley photographed the impact cloud again and found that it had approximately tripled in size:
High-resolution images from the Hubble Space Telescope reveal what's happening: turbulence and jet streams in Jupiter's atmosphere are causing the cloud to spread out. The vast impact site is now tens of thousands of times wider than the 100m-class comet or asteroid that created it.
The expansion of the cloud makes it easier than ever to see through a backyard telescope: sky map. The cloud is located near Jupiter's System II longitude 210°. For the predicted times when it will cross the planet's central meridian, add 2 hours and 6 minutes to Sky and Telescope's predicted transit times for Jupiter's Great Red Spot.
|
|
置顶卡
变色卡
千斤顶
显身卡
