On March 2, 2004, the European Space Agency launched the space probe Rosetta with its lander Philae. Its mission was to visit a comet and send back data as to its physical and chemical makeup. After spending more than 10 years and nearly 4 billion miles in pursuit, Rosetta caught up with the comet Churyumov-Gerasimenko whose 6.5 year elliptical orbit lies between those of Mars and Jupiter.

On November 12, 2014, the Philae lander settled on to the surface of the comet while Rosetta sent back hundreds of pictures of its surface. Philae reported back the presence of glycine, an amino acid essential for life, and phosphorous in the composition of the comet. This finding could be a partial vindication for the eminent British astronomer Sir Fred Hoyle who proposed the theory that life could have been seeded on Earth by microbes brought from outer space by comets.

Rosetta is still sending back data and photos from the comet and is some 288 billion miles from Earth.

Focus on the planet

With a little luck, viewers will be able to see the five naked-eye planets in the evening sky over the course of the month. Mercury makes it above the western horizon during the final week of July just to the upper left of Venus. A good opportunity to view Mercury will be on July 30 when it is very near the bright star Regulus, however, it may be difficult to distinguish between the star and the planet.

Venus is very low in the west around mid-month in company with Mercury but sets a half-hour after sunset. The best chance to view the two innermost planets will come on the last day of the month when Venus, Regulus and Mercury form an ascending diagonal line, right to left, low on the western horizon a half-hour after sunset.

Mars rises in the south at nightfall and is getting steadily dimmer and smaller as it moves away from us. Nonetheless, the Red Planet will continue to outshine all of the stars in its neighborhood and can continue to show surface features in a medium or larger telescope.

Jupiter is well up in the west an hour after sunset and sets around midnight. Its four major moons put on a show with one, Ganymede, crossing the face of the giant planet starting around 10:50 p.m. Friday, July 1, and lasting about three hours.

Saturn is high in the south around 10:00 p.m. Friday, July 1, with brilliant Antares to its lower right. The ring system is near maximum tilt for viewing with the two rings and Cassini division readily seen as is the major moon Titan and several lesser moons.

Uranus rises in the southeast just before midnight, and its blue-green disk will be best spotted just before dawn.

Neptune rises in the south around midnight and can be seen as a blue-gray disk among the stars of Aquarius during morning twilight. On Friday, July 22, Neptune will be occulted by a waning gibbous moon as it passes in front of the planet.

July events

1: Sunrise, 4:53 a.m.; sunset, 8:25 p.m. Look to the south around 10;00 p.m. where Saturn rides high with Antares to its lower right. Mars is to the extreme right of Saturn.

4: The Earth is at aphelion or greatest distance from the sun today. New moon, 7:01 p.m.

8: Look for Jupiter high in the western sky an hour after sunset with the crescent moon to its lower right.

11: First quarter moon, 8:52 p.m.

13: The moon is at apogee or greatest distance from the Earth today.

15: The moon is just above Saturn tonight with Mars further to the lower right and Antares just below Saturn.

19: Full moon, 6:56 p.m. The full moon of July is called the Hay Moon or Thunder Moon.

20: The sun enters Cancer on the ecliptic.

22: The sun enters the astrological sign of Leo.

26: Moon in last quarter, 7:00 p.m.

27: Moon at perigee or nearest approach to Earth.

29: The moon nearly occults or obscures Aldebaran in the morning sky.

31: Sunrise, 5:19 a.m.; sunset, 8:03 p.m.

Send astronomical queries to Clair Wood at cgmewood@aol.com or care of the Bangor Daily News, Features Desk, P.O. Box 1329, Bangor, Maine 04402.