by Aldo Hugo Olguín
Professor of Mathematics, Physics and Cosmography
July 2010 will be an unforgettable month! July is known as the month of aphelio, the point at the year when the Earth is furthest from the Sun, which the Earth reaches every first week of July.
It is during this month that we can observe one of the most beautiful sights, and those who live in latitudes like San Luis’ have the privilege of being able to observe the very center of the galaxy we are part of, the Milky Way.
If we look up to the highest point in the sky (Zenith) at midnight, we will easily find Scorpio and Sagittarius, a zone densely populated by nebulous-like heavenly bodies which shine among the galactic dust and gas. Part of the zenithal light we will be receiving comes from the nucleus of the Milky Way, from a highly dense heavenly body located at the center of the galaxy at such a distance which can be calculated in about 25,000 years. Thus, we could ask ourselves: what happened on Earth at that time? What was the sky like?, and so on. The fact is that the light we see travels throughout the space for a long time, which varies according to the distance there is between the Earth and the object we observe – the furthest the object, the longer the time the light will take to get to the Earth; for example, it is 8 minutes from the Sun, it is 2 seconds from Venus, the star we see at dusk, and it is about 1 second from the Moon. What we see is no more than a reflection of the past.
Other extraordinary beautiful – though simple- events you cannot miss are:
- July 11th from 4pm (local time) on, partial sun eclipse (do not observe it directly. Use a perforated carton so that you can project the sun over another white carton. In this way, you will be able to see and take photographs of the sun without having your eyes hurt).
- July 15th at dusk, heavenly bodies’ reunion: the moon will be near Venus, Mars and Saturn among the Leo stars (look for the crescent moon, next to the horizon at dusk, by the planets).
- July will say goodbye with a beautiful meteors rain which will finish by the end of August.
Happy Friends’ Day for Everyone!
