Anthropocene Epoch: Humans change planet Earth
By Phyllis Burton Pitluga

Geologists are discussing that a new epoch in Earth’s history is upon us and should be named the Anthropocene Epoch. Our activity on this planet has so changed the physical and chemical nature of oceans, fresh water, glaciers, land and air that we are the major force. Starting 200 years ago, humans reached a population of one billion people (today we are at six billion). During this time we moved from farms to cities, manual and animal labor to mechanization and from fire to fossil fuels. There is even a suggestion that the Anthropocene Epoch should begin 8,000 years ago when people started to clear forests, grow crops and develop animal husbandry. The official current epoch is called the Holocene Epoch. It goes back 10,500 years with the ending of the last Ice Age. Our planet was so perfect for life to develop that this new Anthropocene Epoch is a major jolt to what we are doing with it: caretakers or careless users. 

Time to change clocks in Mexico

Here in Mexico, in 2008, we set our clocks ahead on Sunday, April 6, at 2am. Mexico has three time zones. The Central Time Zone (CDT) spans the Yucatán Peninsula to west of Guadalajara. The western states of Sonora, Chihuahua, Sinaloa, Nayarit and Baja California Sur are in the Mountain Time Zone. Just Baja California Norte is in the Pacific Time Zone. Only Sonora doesn’t change to Daylight Saving Time, just as Arizona doesn’t change time during the year. People of these desert climates don’t want more sunlight during their active hours.

We return to Central Standard Time (CDT) by turning back our clocks an hour on Sunday, October 26, at 2am. The dates for this change should be a symmetrical number of weeks before and after the June Solstice to have an equal number of hours of daylight on the first day as the last day of the Daylight Saving Time (DST) period. Thus, in Mexico we should change back on September 7, but government people make these decisions, seemingly not consulting astronomers.

Phyllis Burton Pitluga is Astronomer Emerita of the Adler Planetarium and Astronomy Museum, Chicago, and is now a San Miguel resident.

Sky Calendar April 2008

By following the Moon as the biggest and brightest “pointer” in the sky, during the month you can identify different planets and bright stars. On following nights you can relocate them, but without the Moon, which moves about 25 times its own diameter from one night to the next. The Moon is much closer than the planets of our solar system and the stars are even farther. So, when the Moon appears close to a celestial light, they are truly separated by millions, billions or trillions of miles. 


April 4, Friday: The Waning Crescent Moon passes above Venus.

April 5, Saturday: New Moon and the closest for the month, so the high tides along the coast will be greater. 

April 8, Tuesday: Waxing Crescent Moon passes above the Pleiades star cluster.

April 12, Saturday: First Quarter Moon passes above Mars.

April 13, Sunday: The slightly Gibbous Moon passes just above the Beehive star cluster.

April 15, Tuesday: The Gibbous Moon passes below Regulus, the brightest star of the constellation Leo-the-Lion and even farther below Saturn. 

April 20, Sunday: Full Moon and Leonid Meteor Shower (the light of the Full Moon will wash out the fainter “shooting stars”).

April 23, Wednesday: Waning Gibbous Moon passes beneath Antares, the brightest star of the constellation Scorpius.

April 27, Sunday: Waning Gibbous Moon below Jupiter.

April 28, Monday: Last Quarter Moon, Mars below Pollux, one of the Gemini-twin stars.