Mars rises in the constellation Taurus about 4:40 a.m. on Monday. On July 22, Mars and Jupiter are separated by less than half a degree at 5:12 a.m. At that time, Mercury sits 8 degrees below, right on the east-northeast horizon.
Venus can be found in the Beehive, or Praesepe (Messier Object 44) on Wednesday. The 2˝-day-old waxing crescent moon is seven degrees from Venus on July 10.
Venus is about one degree away from Regulus, the heart of Leo, the Lion, on July 22, and is joined by a waxing gibbous moon on July 16. Can’t find Leo? Just look for the “backwards question mark” or sickle in the southwest.
If you want to see Neptune, get out your binoculars at midnight on July 24. Place the waning gibbous moon right outside the field of a pair of 7 x 50s at the 10 o’clock position. Neptune will be the dimmer object in the center of the field, with the brighter star Sigma Aquarii slightly below and to the left.
The Southern Delta Aquarid meteor shower will occur in the early hours of July 29. While one of the stronger summer showers, the waning gibbous moon rises earlier around midnight, and may wash out all but the brightest meteors. This shower is thought to originate from the debris trail of comet 96P/Macholz.
The appearance of Comet ISON late this year remains unsettled, as its close solar pass may completely evaporate the comet’s nucleus. We may see nothing — or maybe the comet of the century. Stay tuned.
Q: How big is the universe? — C.H., Canton
A: We cannot determine the actual size, or even the shape of our universe. But we can estimate the size of the observable universe.
We know from scientific observation that the universe — space itself and everything in it — came into being about 14 billion years ago. That’s what has been called, not too accurately, the Big Bang. Space has been expanding over that period, and the Hubble Space telescope has photographed galaxies nearly 14 billion light-years distant.
But while the light falling on the Hubble’s camera has traveled over the last 14 billion years, space itself and everything in it has continued to expand in that period at a rate known as the Hubble flow. Therefore, those galaxies photographed by the Hubble are now actually 46 billion light-years away from us.
Consequently the observable universe, after 14 billion years of expansion, is about 92 billion light-years across. Beyond that, we just don’t know.
The Hoover-Price Planetarium will present Pluto Again? beginning July 8. Since 1931, Pluto has been the problem child of the solar system, and was classified as a dwarf planet in 2005. Astronomers continue to find new moons of this little sphere. Should we once again reclassify Pluto?
The program will be shown at 1 p.m. Saturdays and 2 p.m. Sundays. Through Labor Day, there will also be weekday showings at 1 p.m. The Hoover-Price Planetarium is located inside the McKinley Presidential Library & Museum in Canton. The show is free with museum admission.
David L. Richards is director of the Hoover-Price Planetarium at the McKinley Presidential Library and Museum, 800 McKinley Monument Drive NW, Canton, 44708, www.mckinleymuseum.org. He can be reached at 330-455-7043 or email firstname.lastname@example.org.