Download The Night Sky

The Night Sky
June offers the last chance this century to view one of the rarest of astronomical
phenomena. In the early evening of June 5th, the planet Venus will pass directly between the
Sun and Earth, an event known as a transit. The planet will be seen as a small black dot moving
slowly across the face of the Sun. Such an alignment is so rare that it won’t happen again until
the year 2117. However, one should never look at the Sun without proper eye protection or
serious damage to the eye and even blindness could result. For a safe and enjoyable experience,
ETSU and Bays Mountain astronomers will have numerous telescopes with solar filters set up on
the campus of ETSU to provide the public with the proper means to view this unique
astronomical event. The telescopes will be set up on an athletic field on the west side of the
main ETSU campus, just north of the Center for Physical Activity. Parking is available between
the athletic field and the tennis courts. The transit will be visible for approximately two hours. It
will begin at 6:04 PM when Venus first reaches the limb of the Sun. However, the small black
dot will not become fully visible until 6:22 PM when it is completely within the disk of the Sun.
The dot will then very slowly crawl across the solar disk, the entire journey taking almost seven
hours. Visitors should plan, however, to get their view of the transit well before sunset as the
Sun will be dropping below the horizon and no longer visible from the ETSU campus by 8:30
PM that evening.
The day before Venus puts on its celestial show, a partial lunar eclipse occurs on the
morning of June 4th. However, from East Tennessee, the eclipse will barely be noticeable as the
Moon will only enter the outer (penumbral) shadow of the Earth. The event starts one hour
before moonset at 5:00 AM placing the Moon very low in the western sky.
Mars and Saturn remain visible in the evening sky all month. Mars is high overhead at
sunset, but will be moving from the constellation Leo into Virgo by the end of the month. It
remains obvious to the naked eye against the fainter background stars due to its distinctive
orange coloring. Saturn will spend the month just to the north of Virgo’s brightest star, Spica. It
too is recognizable by its yellowish color versus the blue-white color of Spica.
Finally, the official start of summer in the northern hemisphere always begins in June and
is signaled by the summer solstice. This is when the north pole of the Earth’s axis of rotation has
its maximum tilt towards the Sun. Around this time, the Sun is at its highest in the daytime sky
with the hours of sunlight also at a maximum. This solstice will occur on June 20 at 7:09 P.M.
(EDT).
Regular public open houses at the Powell Observatory and programs at the ETSU
Planetarium are not offered during the summer months. They will begin again in September.
Written by Dr. Gary Henson, Department of Physics and Astronomy. He can be reached via
Email at [email protected]. Astronomy related information for the public, including a link to
ETSU astronomy public events, can be found at http://www.etsu.edu/physics/astronomy.htm