Venus transit on 8 June 2004 observed by the
Transition Region and Coronal Explorer


TRACE logged about 1,050,800 web hits on June 8, 2004, requesting 131GB of images and movies

On June 8, 2004, TRACE was the only satellite able to observe the transit of Venus across the solar disk in visible light. Beautiful images were obtained throughout the 6-hour event. As these came into the archives at Goddard Space Flight Center and at LMSAL, they were processed into movies and stills that were made available on the web. Over 40 television stations in the US used these images, and over 700 stories were run on national, cable and local markets across the country through mid morning on 8 June 2004. International media also paid attention. The result was a rush to access TRACE images on our website: we logged over 1,000,000 hits, and exported over 130 gigabytes of data in the 24 hour period starting at the time of the transit. A day after the transit, the internet traffic remained higher than normal by about a factor of five. Among the images is a nice set around the time of 3rd contact, when the so-called 'black drop' effect was observed between 10:57UT and 11:01UT (a short movie can be found below), which is a consequence of the telescope point-spread function and, more interestingly, the light-scattering properties of the atmosphere of Venus.

Here are a few links to other Venus transit observations: Images from the Swedish 1-m Solar Telescope (SST), dutch Open Telescope (DOT), NOAA/GOES-12. Some more are contained in the tables below. The heavy internet traffic related to this event is discussed here on an ABC site.
Venus transit black drop effect in WL

The transit of Venus on 8 June 2004

On June 8 and 9, 2004, TRACE observed the transit of Venus. This site contains images and movies of that event, and links to other sites. The five entries of the second table below contain information on, or links to
  • other sites on the Venus transit.
  • the observing program of TRACE, the satellite pointings, and the expected times of contacts of Venus and the solar limb as seen from TRACE.
  • the transit of Mercury on 7 May 2003 as seen by TRACE.
  • the transit of Mercury on 15 November 1999 as seen by TRACE.
  • information on TRACE, its science goals, and solar physics in general.
TRACE images and movies may be used without restrictions. We appreciate an acknowledgement indicating that the Transition Region and Coronal Explorer, TRACE, is a mission of the Stanford-Lockheed Institute for Space Research, and part of the NASA Small Explorer program.

NASA image gallery feature.

Venus transit composite in WL Venus transit composite in WL Venus transit seen from Australia
The top two images on the left are composites showing the transit of Venus on 8 June 2004 as seen in the TRACE visible light (top) and 1600Å (bottom) channels. As in the Mercury transits in 1999 and in 2003, the trajectory of the planet appears to go up and down. This is a consequence of the parallax introduced by the motion of TRACE around the Earth: as TRACE moves over the Earth's north polar regions, Venus is projected southward on the Sun, and vice versa. The composite shows Venus at more or less regularly spaced time intervals. There are a few images missing at times that TRACE changed its observing mode, or when the data transmission to the ground station failed. But allowing for those few, the images towards the north appear to be closer spaced than those towards the south. That too is to be expected from an orbiting satellite, because when TRACE moves with the planet (over the Earth's south pole), the parallax causes subsequent images to be spaced by less than is the case when moving against the planet's direction of motion when over the north polar regions of the Earth.

The bottom image shows a transit image taken in Australia offering an upside-down perspective (from the ABC web.
Line

TRACE 171 A 11:39 UT

June 8, 11:39 UT - 12:09 UT

Venus observed in 171 A passband

quicktime, JPEG Compr
avi, Cinepak Compr

Venus transit black drop effect in WL

June 8, 10:57:52UT - 11:01:24 UT, black drop effect

"To quantify the distance from earth to the sun, known as the Astronomical Unit (A.U.), astronomers embarked on global expeditions to time the transit of Venus from widely separated latitudes. However, for centuries the "black drop" effect--the stretching out of Venus near internal contact--confounded astronomers when they tried to discern the exact moment when Venus touched the inside edge of the sun." See herefor a collection of descriptions. Venus leaving the solar disk in visible light

1. 512 x 512, quicktime, JPEG Compr, 512 x 512, avi, Cinepak Compr
2. Without clock: 512 x 512, quicktime, JPEG Compr, 512 x 512, avi, Cinepak Compr

TRACE 1600 A 10:37 UT TRACE WL 10:37 UT

June 8, 11:00UT - 11:28 UT, third to fourth contact

Venus leaving the solar disk in visible light

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

TRACE 1600 A 10:37 UT TRACE WL 10:37 UT

June 8, 10:37UT - 11:25 UT

Venus seen in ultraviolet light (1600 A)

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

Venus seen on the disk in Visible light and going across the West Limb

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

TRACE 1600 A 10:26 UT TRACE WL 10:26 UT TRACE 171 A 10:07 UT

June 8, 07:43 UT - 10:37 UT

Venus observed in 171 A passband

1. 1024 x 512, quicktime, JPEG Compr, 1024 x 512, avi, Cinepak Compr

Venus seen in ultraviolet light (1600 A)

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

Venus seen on the disk in Visible light

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

TRACE 1600 A 06:34 UT TRACE WL A 06:22 UT

June 8, 05:53 - 07:43 UT

Venus seen on the disk in Visible light

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

Venus seen in ultraviolet light (1600 A)

1. 800 x 512, quicktime, JPEG Compr, 800 x 512, avi, Cinepak Compr
2. 400 x 256, quicktime, JPEG Compr, 400 x 256, avi, Cinepak Compr

Stringing together TRACE pointings

June 8, 04:58 - 07:43: Venus transit and orbital parallax

The field of view of TRACE is small compared to the Sun, so we have to repoint often to follow Venus across the solar disk. This makes it more difficult to look at movies made during the night. But even in these 'choppy' movies, it is clear that Venus appears to move up and down. That is a consequence of the fact that TRACE orbits the Earth, going more or less over the north and south poles. As TRACE moves up and down relative to the plane of the planets in the sky, Venus is seen to move across the Sun in the opposite direction. That parallax effect can be used to measure the distance to the planet, as explained, e.g., here.

Venus seen on the disk in UV light (1600Å channel):

  1. 1024x512, quicktime, JPEG compr., 1024x512, AVI, Cinepak compr.
  2. 512x256, quicktime, JPEG compr., 512x256, AVI, Cinepak compr.

June 8, 05:34 UT: the atmosphere of Venus

This (logarithmically scaled) image of Venus on the eastern limb of the Sun shows a faint ring around the planet. That faint ring, with a brightness of only about 1% of the brightness of the Sun close to its edge, is a consequence of the scattering that occurs in the atmosphere of Venus, allowing some sunlight to show around the edge of the otherwise dark planetary disk. The faint glow on the disk of Venus is an effect of the TRACE telescope.
06:03 UT in WL 06:03 UT in 1600Å 06:05 UT in 171Å

8 June, 06UT: Venus on the disk

These three images show Venus on the solar disk in visible light (top), in the ultraviolet 1600Å pass band (center) and in the extreme ultraviolet 171Å pass band of TRACE. The exposure duration in the 171Å channel is 93 seconds. During that time, Venus moves by approximately 12 pixels, causing motion blurring of the edges of the planet on the leading and trailing sides. In contrast, the UV and WL exposures are less than one second, and the planet's edges therefore sharp.
Venus on the disk in WL Venus on the disk in 1600Å

June 8, 04:58 - 05:47: Venus transit begins (preliminary images)

Venus seen on the disk in visible light:
  1. 800x512, quicktime, JPEG compr., 800x512, AVI, Cinepak compr.
  2. With clock, and different color table: 800x512, quicktime, JPEG compr., 800x512, AVI, Cinepak compr.
  3. 400x256, quicktime, JPEG compr., 400x256, AVI, Cinepak compr.
  4. With clock, and different color table: 400x256, quicktime, JPEG compr., 400x256, AVI, Cinepak compr.
Venus seen on the disk in ultraviolet light (1600Å channel):
  1. 800x512, quicktime, JPEG compr., 800x512, AVI, Cinepak compr.
  2. 400x256, quicktime, JPEG compr., 400x256, AVI, Cinepak compr.

Venus prior ot first contact

June 8, 04:04 UT - 04:33 UT: Venus visible against the high corona

As Venus approaches the Sun, it blocks the extreme ultraviolet radiation emitted by the faint, quiet corona, observed by TRACE in its 171Å passband (characteristic of 1 million degree gas): 512x512, quicktime, JPEG compr.; 512x512, AVI, Cinepak compr.
LASCO C2 23:48UT

June 7, 23:48 UT: Venus approaches the Sun

The LASCO coronagraph on SOHO now shows Venus approaching the edge of the occulting disk in the narrower-field coronagraph (C2).
LASCO C3 13:42UT LASCO C2 13:50UT

June 7, 14:00 UT: Venus approaches the Sun

With only 15 hours to go before first contact of Venus and the solar limb, the LASCO coronagraph on SOHO shows Venus approaching the edge of the occulting disk in the wide-angle coronagraph (C3). Venus is so bright that the detector saturates, causing the wide horizontal stripe centered on the planet. The two images show the fields of view of the C3 and C2 coronagraphs, respectively.
Venus orbit

Other sites on the Venus transit


Venus Transit 2004 (GSFC/SEC ed. forum)
View the Transit Live on the Web with the Exploratorium crew in Athens, Greece!
Other Viewing Options
For detailed maps and transit times
James Cook and the Transit of Venus
Transit of Venus (UK site)
Transit of Venus (French site)
Venus Transit program of ESO (ESO Education & Public Relations Department)
Educational information about the Venus Transit
Venus Transit Contact Times
IMAGE Venus Transit Page
SOHO's Venus Transit Page

Technical details

Technical details and sample movies from test runs

TRACE observing program description, and UTIM.

Movies of the final test run:

Venus Test Program III, movie in visible light, 04:00 UT - 04:47 UT:

  1. 800x512, quicktime, JPEG compr.; 800x512, AVI, Cinepak compr.;
  2. reduced to 400x256, quicktime, JPEG compr.; reduced to 400*256, AVI, Cinepak compr..

Venus Test Program III, movie in UV/1600 light, 04:00 UT - 04:47 UT:

  1. 800x512, quicktime, JPEG compr.; 800x512, AVI, Cinepak compr.;
  2. reduced to 400x256, quicktime, JPEG compr.; reduced to 400*256, AVI, Cinepak compr..

Test movies, early set:
Venus Test Program I, movie in 171 covering 03:32 UT - 05:38 UT
Venus Test Program I, movie in 171 covering 05:51 UT - 10:47 UT
Venus Test Program I, movie in 171 covering 11:54 UT - 14:59 UT
Venus Test Program I, movie in 1600 covering 04:48 UT - 11:48 UT
Venus Test Program I, movie in WL covering 04:48 UT - 11:48 UT


Mercury transit, 7 May 2003

The transit of Mercury on 7 May 2003

This composite shows the transit of Mercury (4800 km diameter) across the solar disk, as observed by TRACE in its 1600Å pass band on 7 May 2003. The composite shows the position of Mercury roughly every 450 seconds. The wobble on the disk crossing is a parallax effect caused by the orbital motion of TRACE around the Earth; this wobble could - if we didn't know it already - be used to determine the distance of Mercury to the Sun! Notice, by the way, that Mercury moves up and down as well as left to right during the TRACE orbit, modulating the spacing of the disks in this composite image. The transit can also be seen in this (AVI/cinepack) movie. For more TRACE movies and other links to Mercury-transit observations, click here. SOHO observations can be seen here; notice there's no wobble there, because SOHO does not orbit the Earth!
Line
Mercury transit

The transit of Mercury on 15 November 1999

A collage of images taken with the Transition Region and Coronal Explorer. The images are taken in the 171-Angstrom channel (Fe IX/X; characteristic of material at approximately 1 million degrees), the 1600-Angstrom passband (UV line and continuum emission; mostly showing material at around 5500 degrees on the disk, and material at about 100,000 degrees just above the solar limb), and a broad-band white-light channel (around5500 degrees). Note that whereas the planet Mercury just comes within the edge of the Sun in white light, it comes much further onto what appears as the disk in the extreme ultraviolet (EUV) image at the top: the offset between the white-light and EUV limbs is approximately 4,000 (plus or minus 200) km. This is caused by the envelope of chromospheric material immediately above the surface: white light goes right through is, but EUV light does not. The EUV doesn't shine through until much higher. This demonstrates clearly that the Sun is just a gaseous sphere without a well defined surface: at different wavelengths the Sun has a different size.
Model pdf file

TRACE and solar physics

The Transition Region and Coronal Explorer is a NASA Small Explorer (SMEX) mission to image the solar corona and transition region at high angular and temporal resolution. The goal of the TRACE science investigation is to deepen our understanding of the effects of the Sun's magnetic field on its own atmosphere, and to help us understand the changes that this causes in the heliosphere between Sun and Earth, and in the space around Earth, including our own atmosphere. TRACE is thus an important component of the Sun-Earth Connection theme of NASA. Click here for an introduction to the TRACE satellite and its scientific goals. The TRACE mission is described briefly here, and the instrument here. A paper model of the TRACE satellite can be made using this pdf file. Images and movies of a diverse collection of solar phenomena can be viewed here.

  • For an introduction to solar physics, have a look at two web sites (1, 2) that describe the Sun and show it in its many guises. Two sites provide glossaries (1, 2) that explain solar terminology. With that background, have a look at an explanatory slide show that shows the solar surface and its outer layers, the environment between sun and Earth, the effects of the Sun on the Earth, and even the future fate of the Sun as it evolves. Then there is a slide show showing a collection of different images of the Sun, with some explanation. And for something completely different, you can even listen to the sounds in the Sun that are generated by the turbulent motions of the gas near its surface, and read what that is used for in the field of helioseismology (1) to probe the internal structure of the Sun. There is also a K-3 lesson on the sounds of the Sun.
  • Among the vast amount of information that can be found on the web about the Sun in general, there are several brief introductions to the Sun There is a NASA educational site on the Sun including a picture of the sunspot cycle, and (links to) the solar corona and solar wind, and even an account of a flare observation by Carrington in 1859. Some diagrams, numbers, and more links forming another introduction to the Sun, and a collection of pictures and movies on a short tour about the Sun can also be explored. Australia's IPS Radio & Space Services developed an extensive set of pages containing links to a series of occasional articles by IPS staff and their colleagues on the Sun and its effects on the Earth. Or try this overview of the Sun, the solar system, and some of the nearby star systems.
  • The Stanford Solar Center presents a collection of fun educational activities where you can explore the Sun's tangled magnetic field, its turbulent surface motions, the dramatic sunspot cycle, and even what magic happens in the solar interior.
  • A large collection of pretty pictures of the Sun-Earth connection can be found at Goddard's ISTP outreach pages
  • There is also a collection of images of the solar eclipses of 24 October 1995 and 3 November, 1994, with ground-based eclipse movies, YOHKOH data, ...
  • The International Solar Terrestrial Physics (ISTP) Program WWW INDEX contains links to different sites related to the interaction of the Sun and the Earth.
  • The Space Studies Board of the National Research Council compiled this summary of the practical consequences of space weather. One particular example is a large-scale power outage caused by a solar eruption.
  • Space Link: an Aeronautics and Space Resource for Education
  • International Space Physics Educational Consortium

Line

Some of the press coverage:

The Transit of Venus was a huge success. The preliminary TV stats indicate animation and graphics produced in the pre-launch Video File package, along with excepts from TRACE were used in over 700 stories on national, cable and local markets across the country through mid morning on 8 June 2004. In addition, the accompanying satellite media tour was among the most successful ever produced from Goddard. Producers Rachel Weintraub and Rani Chohan lined up 41 stations this morning. Phil Plait, Beth Brown and Enectali Figueroa provided excellent commentary during the interviews. Animation and visualization support for this project was provided by the Sun Earth Connection Theme. Title: VENUS TRANSIT LIVE SHOTS Date: June 8, 2004 601 - 605 Roll B-Roll 606 - 610 WDBJ - Roanoke, VA 611 - 615 WSPA - Greenville, SC 616 - 620 WHEC - Rochester, NY 621 - 625 WCCO - Minneapolis, MN 626 - 630 KXAS - Dallas, TX 631 - 635 WWSB - Tampa FL 636 - 640 WLWT - Cincinnati, OH 641 - 645 WROC - Rochester, NY 646 - 650 WJHL - Johnson City, TN 651 - 655 KARE - Minneapolis, MN 656 - 700 WDBJ - Roanoke, VA 706 - 710 WJBK - Detroit, MI 711 - 715 KSDK - St. Louis, MO 716 - 720 KWCH - Wichita, KS 721 - 725 WFIE - Evansville, IN 726 - 730 KUSA - Denver, CO 736 - 740 WBOC - Dover, DE 741 - 745 WFAA - Dallas, TX 746 - 750 WGN - Chicago, IL 751 - 755 KXAN - Austin, TX 756 - 800 WREG - Memphis, TN. 801 - 805 KIDK - Idaho Falls, ID 806 - 810 KBCI - Boise, ID 811 - 815 KWGN - Denver, CO 816 - 820 KCNC - Denver, CO 821 - 825 KMPH - Fresno, CA 831 - 840 MSNBC 841 - 845 KPIX - San Francisco, CA 846 - 850 KING - Seattle, WA 851 - 900 KXTV - Sacramento, CA 906 - 910 KPNX - Phoenix, AZ 911 - 915 KXLY - Spokane, WA 916 - 920 KVVU - Las Vegas 921 - 930 CNN ESPANOL 930 - 940 AZTECA AMERICA - 940 - 950 KVEA - Los Angeles, CA Telemundo 951 - 1000 KXLN - Houston, TX 1016 - 1020 Associated Press Television News 1021 - 1025 KSAZ, Phoenix, AZ 1041 - 1045 KFMB - San Diego, CA

Line
Web stats:

Line
 

| LMSAL Home | Mission | Instrument | Team | Operations | Results | Images | Movies | Education | Site Info. |