Almanac
Tatooine Returns: Artist's Depiction of a Planet Circling Double Stars. image courtesy NASA
Venus is the bright object in the western skies at dusk. At the beginning of the month Jupiter is some 40 degrees above Venus. Venus moves rapidly to the east and by the end of the month, the two planets will be no more than a fist-held-at-arm’s-length away from each other.
Feb 7: Full Moon: This month it is known as Snow Moon, for obvious reasons. Some Native American tribes called it the Full Hunger Moon or Little Famine Moon because the harsh weather made hunting difficult. The Cherokee, forced to gnaw on bones and drink bone marrow soup, named it the Full Bony Moon. The Celts call the full moon of February the Moon of Ice.
Feb 9: Look to the east for the rising moon between 8 and 9pm. Fire-colored Mars will be visible to its left (north). Mars is moving retrograde in the constellation of Leo. An equal distance to the left of Mars you can find Denebola, the tail of the Lion.
Feb 9-23: This is a good time to see the zodiacal light about an hour and a half after sunset. Look to the west for a tall pyramid of light on the line between Venus and Jupiter.
Feb 14: Last quarter moon.
Feb 21: New moon.
Feb 23 and 24: After sunset, look to the west for the newly born slender crescent moon moving upward toward Venus.
Feb 25 and 26: The moon passes Venus and continues upward to reach Jupiter
Vanishing dark skies
We had a gathering of 2500 astronomers at the winter meeting of the American Astronomical Society in Austin, Texas this January. One of the continuing concerns expressed at these meetings is the increasing brightness of our night skies. We are raising a generation of people who don’t know what the Milky Way looks like.
Pity those who live in a bright city where it never gets completely dark at night. But there are hazards even in Crestone. Consider TV and computer monitors. They emit light that is rich in blue wavelengths. Recent health studies show that excessive exposure to these blue-rich light sources at night hamper or even shut down our body’s production of melatonin—a substance that helps us sleep and also plays a role in fighting off diseases such as cancer. Researchers are now looking at the links between people who work at night and higher rates of breast and prostate cancer. Take time out from your TV or monitor and go outside at night greet our Milky Way.
Planets galore!
Einstein's Ring: A Distant Galaxy Enlarged into a Ring by Gravity Hubble image courtesy NASA
One of the most exciting announcements at the meeting involved recent discoveries about other planets in our galaxy. We once wondered: ARE WE ALONE? Now it appears there are as many planets in our galaxy as there are stars: a whopping 200 billion planets. Considering that there are as many galaxies in our universe as there are stars in our galaxy, that’s a lot of planets.
The remarkably successful spacecraft named Kepler searches for planets by continuously monitoring the brightness of some 150,000 stars, looking for dips in their brightness caused by a planet crossing the surface of the star. It has now identified 3035 exo-planets.
In September, Kepler discovered one planet that orbits two suns similar to Tatooine, the home of Luke Skywalker of Star Wars. Since the planet orbits binary (double) stars, it is known as a circumbinary planet. That means two sunrises and two sunsets every day. George Lucas, stand aside!
I relish the comment by John Knoll of Industrial Light & Magic, a division of Lucasfilm Ltd., in San Francisco. “… more often than not, scientific discoveries prove to be more spectacular than anything we dare imagine. There is no doubt these discoveries influence and inspire storytellers. Their very existence serves as cause to dream bigger and open our minds to new possibilities beyond what we think we know.”
Two more circumbinary planets were announced at the meeting in January. What is most wonderful is that both of these planets lie in the Goldilocks zone of the stars, neither too hot nor too cold for liquid water. In this habitable zone, life could gain a foothold.
I worry for the residents of these planets. Their orbits are close to being unstable. If they were 25% closer to the suns, the cumulative gravitational tugs by the two suns would drive them into unstable orbits with huge swings in distance, eventually resulting in their being flung outward. Can you imagine the despair? Winters are getting colder and summers are hotter. Eventually, they will be ejected into the utter darkness of interstellar space. We are struggling on Earth with our own global warming. It is a very serious problem, but at least we have a chance to try to reverse it.
The most astonishing result presented at the meeting comes from a study based on gravitational lensing due to the curvature of space around a star. In this technique, one star acts like a magnifying lens to brighten the light from a background star. If the foreground star has a planet, it also produces a brightening. These measurements indicate that, on the average, every star in our galaxy has at least one planet circling it. Two-thirds have a planet with the mass of the earth. There are some 1,500 planets within 50 light-years of Earth. Even better there 10 planets within 10 light years, giving us time for several phone calls during a lifetime.
We have known for some time that the bending of space by the gravity of galaxies produces the same effect. Very distant galaxies, at the edge of the universe, are enlarged and brightened by this process. The picture taken by the Hubble Space Telescope shows a galaxy at a distance of 10.7 billion light years enlarged by a nearby galaxy and turned into a ring. Look carefully at the ring and you can see the distorted arms of the distant spiral galaxy. Without this magnifying lens it would appear as an infinitesimally small spot of light. Can you believe there may be more than a hundred billion stars and planets contained within that ring?
