Seeing Stars with James Wooten: June 2012

Mars remains an evening object this month. Face south at dusk and look for a reddish star to the left of Regulus in Leo. However, Mars continues to fade a little bit each night as Earth pulls away from it. This summer, you can watch Mars quickly approach Saturn, which it will pass on August 15.

Saturn is now in the south at dusk this month. Saturn is just above the star Spica in Virgo.

Meanwhile, Jupiter emerges into the morning sky. Look for it low in the east/northeast at dawn; it outshines all stars in that direction.

sky map june 2012

Venus joins Jupiter in the morning sky by late June.  On June 5, Venus passes directly in front of — or transits — the Sun (see below). In the weeks after that, Venus shifts into the morning sky as it pulls ahead on its faster orbit.  The emergence of Venus into the morning sky is quite dramatic — the brightest celestial object aside from the Sun and Moon is noticeably higher each morning. By June 30, Venus will be close to Jupiter at dawn.

The Big Dipper is above the North Star, with its handle pointing up. From that handle, you can “arc to Arcturus” and then “speed on to Spica;” those stars are in the south at dusk. Leo the Lion is high in the west at dusk.

Antares, brightest star of Scorpius the Scorpion, is in the southeast, with the “teapot” of Sagittarius rising behind it.  The Summer Triangle has fully risen in the northeast; the stars of summer are here.

Mercury takes Venus’ place as an evening star during June. Having just emerged from behind the Sun, Mercury enters the western sky at dusk, where it remains for the rest of the month.  Of course, Mercury is not nearly as bright as Venus, but it still outshines most stars.  Watch the sunset, then look for the brightest “star” in western twilight.  This is Mercury.  In July, it fades and leaves the evening sky.

Like last year, George Observatory opens to the public on Friday nights as well as Saturday nights during the summer.  Also, we’re adding a special “Sun-day” program on Sunday afternoons beginning June 10 that will feature solar observing on sunny days and Sun-related Discovery Dome shows if cloudy!

Moon Phases in June 2012:
Full                               June 4, 6:11 a.m.
Last Quarter                  June 11, 5:42 a.m.
New                              June 19, 10:02 a.m.
1st Quarter                     June 27, 10:29 p.m.

On Tuesday, June 5, Venus passes between Earth and Sun, and is not up at night. This happens every 584 days, and is normally no big deal. This time, however, the alignment is exact, and we can see Venus transit the Sun.  You can come observe this event at any of our three museum facilities.

Transit of Venus at HMNS

At 6:07 pm on Wednesday, June 20, the Sun is directly overhead at the Tropic of Cancer — the farthest point north where this is possible. This means the Earth’s North Pole is tilted towards the Sun as much as possible. Therefore, this date is the summer solstice. In the Northern Hemisphere, we have more daylight and less night than on any other date.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement.

To enjoy the stars in any weather from the comfort of the HMNS Planetarium, click here for a full schedule.

Seeing Stars with James Wooten: Join us for a once-in-a-lifetime viewing of Venus in transit June 5

Mark your calendars for Tuesday, June 5, people.

The Houston Museum of Natural Science invites the public to observe a rare and special event on the afternoon of Tuesday, June 5. On that date, the planet Venus will transit the Sun, appearing as a black dot against the Sun’s disk. Weather permitting, the Museum will provide telescopes with filters to safely observe the Sun near the sundial just outside the Museum’s main entrance, as well as at the George Observatory and at our museum in Sugar Land.

A photograph taken of the 2004 transit of Venus at 3:39 p.m. Hong Kong time from Tuen Mun, New Territories, Hong Kong.

What’s the big deal?

On June 5, Venus passes the Earth on its faster orbit around the Sun. Venus’s orbit is between ours and the Sun, so it passes between Earth and Sun about once every 584 days. However, since Venus’s orbit is tilted by about five degrees to our own, it usually “misses” the Sun by a wide margin as seen from Earth. But on June 5, Venus lines up almost exactly with the Earth and the Sun. This causes Venus to appear as a black dot silhouetted on the Sun’s disk, an event called a “transit.” Only Mercury and Venus can transit the Sun because they are the only planets that pass between the Earth and Sun.

How often does this happen?

Transits of Venus occur in pairs eight years apart — and then not again for more than a century. Because of the way Venus’s orbit is aligned, transits occur only in June or December. This is the second of this pair of transits (the other, not visible in Houston, occurred in June 2004). The next transit visible here in Houston will occur the morning of December 8, 2125.

So how do I see Venus on the Sun’s disk?

Venus remains in front of the Sun for about six hours. Its disk will be over 30 times smaller than the Sun’s — roughly the size of a sunspot. To view the transit, we will provide solar telescopes and solar projection devices at the Museum, at the George Observatory, and at our Museum in Sugar Land. We will also have special solar glasses (the same kind used to watch eclipses) for purchase at all three locations.

As the transit begins, Venus will appear as a small dot on the right side of the Sun low in the western sky. Unlike any sunspots present, Venus will move quite noticeably across the Sun’s disk. Also, sunspots can be irregular in shape, while the disk of Venus is round. The transit begins in the afternoon at 5:09 p.m. and will still be in progress at sunset at 8:19 p.m.

If the Sun was still up, we would see Venus exit the Sun’s disk at 11:31 pm. Due to the trees surrounding Hermann Park and the deck at George Observatory, we will observe at these sites until 7:00 pm. At Sugar Land, however, the clear horizon means we can observe the Sun until 8:00 p.m.

At all three Museum locations, we will have free planetarium previews of the Venus transit, illustrating why it happens and why it is so rare. We’ll also take a virtual voyage to the planet. These special shows will be offered at 4:00, 4:15, 4:30, and 4:45 p.m. in preparation for the event beginning at 5:09 p.m.

Transit of Venus at HMNS

This is the last transit of Venus that anyone alive today will ever be able to see, so don’t miss it!

Do not attempt to observe the Sun with the naked eye or through an unfiltered telescope. Failure to use appropriate filtration may result in permanent eye damage or blindness.