A Christmas Star for SOHO
The planets Venus and Jupiter will pass less than
42 arcseconds apart on May 17. Because the pair is so close to
the Sun, only the Solar and Heliospheric Observatory will have
a good view of the close encounter.
Nevertheless, you can still monitor the encounter thanks to the ESA/NASA Solar and Heliospheric Observatory (SOHO). SOHO has an advantage over most stargazers. Coronagraphs on the satellite can block out the Sun's bright light in order to see nearby stars and planets as well as the Sun's faint corona. The conjunction will be easy to see in images from SOHO's wide field coronagraph that are posted on the SOHO realtime images web page.
Above: On May 15, 2000, SOHO's wide field coronagraph recorded this image of the Sun surrounded by Mercury, Venus, Jupiter and Saturn. A well-known asterism The Pleiades is also visible in the upper left of the image. The blue disk blocks out the Sun's bright light; the white circle near the center shows the true size of the Sun. At 1030 UT on May 17, Venus and Jupiter will be less than 0.01 degrees apart.
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This close conjunction has already been compared to the 2 B.C. conjunction of the same planets that is often identified as the "Christmas Star" reported in the book of Matthew.
In "The Star of Bethlehem: An Astronomical and Historical Perspective," Susan S. Carroll writes:
On June 17, 2 BC, Venus and Jupiter joined .... in the constellation Leo. The two planets were at best 6 (arcseconds) apart; some calculations indicate that they actually overlapped each other. This conjunction occurred during the evening and would have appeared as one very bright star. Even if they were 6 apart, it would have required the sharpest of eyes to split the two, because of their brightness.
Although Venus and Jupiter will appear to be very close together
on May 17, there's no danger of a collision. The two are really
very far apart. Venus will be 257 million km from Earth, while
Jupiter will be 896 million km away. The two are separated from
each other by a comfortable 639 million km.
As Venus passes by Jupiter on May 17 the five classical planets (Mercury, Venus, Mars, Jupiter and Saturn) will span just 19° 25'. The cluster is too near the sun for naked-eye observations, but it's perfect for SOHO coronagraphs, which will be able to see all of the planets except Mars.
Above: This computer animation shows the relative positions of Jupiter and Venus as seen from Earth on May 17, 2000. The six-frame sequence begins at 0830 UT and ends at 1330 UT. The minimum separation between the two planets occurs near 1030 UT. Also shown are the Galilean satellites Io, Europa, Ganymede, and Callisto. The horizontal field of view is approximately 15 arcminutes (the angular separation between Callisto and Jupiter is approximately 7').
SOHO is a cooperative project between the European Space Agency (ESA) and NASA. The spacecraft was built in Europe for ESA and equipped with instruments by teams of scientists in Europe and the USA.Web Links
-real-time images, screen savers, and more
The Star of Bethlehem: An Astronomical and Historical Perspective -- by Susan S. Carroll
Planetary Alignments in 2000 -- from the Griffith Observatory
Venus enhances SOHO's unique picture of planets beyond the Sun -- from the European Space Agency
SOHO Hotshots -- from NASA
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