Among the astronomical community there exists a race to spot the oldest galaxy in the universe. Light travels at about 6 trillion miles per year (Ly), the distance equates to time, so the distance of a galaxy is a measure of its age. Astronomers are looking back toward the dawn of the universe, thought to have originated about 13.75 billion years ago in the Big Bang.
Japanese astronomers, using the Suburu and Keck telescopes in Hawaii, announced this week they have spotted a galaxy situated 12.91 billion light years away. This is not the oldest galaxy claimed as French and California astronomers using the Hubble Space Telescope have reported ages of 13.1 Bly and 13.2 Bly respectively and recently Arizona State astronomers using a telescope in Chile also reported an age in excess of 13 Bly.
The Japanese claim, according to Richard Ellis, a cosmologist at the California Institute of Technology, is the most convincing being backed up by other methods of calculating galactic distances. The full study will soon appear in the Astrophysical Journal.
Focus on the Planets
Two planets each grace the dawn and dusk skies. Dawn sees Venus and Jupiter on the eastern horizon while nightfall brings Mars and Saturn to the western horizon.
Mercury opens the month high in the west about an hour after sunset. This will be the best time to view the innermost planet as it rapidly drops from sight by mid-July.
Venus hovers above the northeastern horizon in the predawn sky as July opens with Jupiter directly above. The two planets will climb higher and separate as the month wears on.
Mars is in the southwest an hour after sunset but continues to grow dimmer and shrink in size. On July 24, look for orange-red Mars to the upper right of the moon.
Jupiter may be found early in the month in the eastern predawn sky directly above neighboring Venus.
Saturn is in the west-southwest as darkness falls. Saturn’s rings are well situated for viewing and its large moon Titan may be spotted passing to the south and north of the planet as it makes its 16-day orbit.
Uranus is a blue-green disk in Cetus while Neptune is the blue-gray disk in Aquarius. Finder charts may be obtained at www.skypub.com/urnep.
1 Sunrise, 4:53 a.m.; sunset, 8:25 p.m. The moon is at perigee or closest approach to Earth. About an hour before sunrise look to the northeast for an ascending line of celestial objects starting with Aldebaran, Venus, Jupiter and finally the Pleiades at the top. About a half hour after sunset Mercury may be found low in the west with the twins, Castor and Pollux, off to its left.
2 According to the astronomical calendar, the midpoint of the year falls at 1 a.m. daylight saving time today.
3 Full moon, 2:51 p.m. The full moon of July is called the Hay Moon, Buck Moon or Thunder Moon.
5 The Earth is at aphelion or farthest distance from the sun for the year.
10 Aldebaran is less than a degree to the right of Venus with Jupiter hovering above them.
11 Moon in last quarter, 9:48 p.m.
12 Venus is at its brightest for this appearance as the “morning star.”
13 The moon is at apogee or farthest distance from Earth.
15 Looking east an hour before sunrise shows a thin crescent moon between and just to the left of Venus and Jupiter.
19 New moon, 12:23 a.m.
20 The sun enters the sign of Cancer on the ecliptic.
22 The sun enters the astrological sign of Leo but astronomically has only just entered Cancer.
24 The western horizon an hour after sunset has the moon with Mars to the upper right and Saturn, with Spica just below, to the upper left. Jupiter is in the eastern predawn sky.
26 Moon in first quarter, 4:56 a.m.
29 Peak night for the Delta Aquarid meteor shower. A poor year to view this occasionally major shower with a full moon coming up on Aug. 2. Look for 15 to 20 faint, fairly fast meteors per hour out of the south near Fomalhaut. The moon is at perigee for the second time this month.
31 The western horizon has Spica (blue-white), Saturn (golden yellow), and Mars (orange-red) forming a triangle an hour after sunset. Sunrise, 5:19 a.m.; sunset, 8:03 p.m.
Send astronomical queries to Clair Wood at firstname.lastname@example.org or c/o Bangor Daily News Style Desk, P.O. Box 1329, Bangor 04402.