ASTRONOMERS and enthusiasts around the world set up their telescopes and witnessed the historic transit of Venus—or its passing between the Sun and the Earth—last June 5 and 6.
A transit is rare a passage of a heavenly body, such as the inner planets Mercury and Venus, across the disk of the Sun.
“This is a rare event as the next transit will be in 2117 [or] after 105.5 years,” Dario Dela Cruz, chief of the space, science, and astronomy section of the Philippine Atmospheric, Geophysical, and Astronomical Services Administration, told the Varsitarian.
This astronomical phenomenon occurs in pairs separated by an eight-year gap. The first pair appears after 105 and a half years while the next one happens after 121 and a half years. The pairs complete the 243-year cycle of the transit. The last transit took place in 2004.
Dela Cruz said transits are comparable to eclipses. But given the distance between the Earth and Venus, he said observers could only notice what appears to be a dot of the gaseous planet passing in front of the Sun.
“In eclipses, since the distance of the Moon to the Earth is close, we see [the Moon] covering the whole surface of the Sun,” he explained.
Transits are not mere visual spectacles. Dela Cruz said they assist in the measurement of distances of heavenly bodies within the Solar System or even beyond.
Each transit can provide scientists and researchers a clearer and better understanding of Venus’ climate and atmosphere. It can also be a basis to discover new planets outside the Solar System or the so-called exoplanets.
The transit was first observed in 1639 by Jeremiah Horrocks, 12 years after Johannes Kepler had predicted its occurrence.
A transit usually happens in four phases. The first contact happens when Venus moves inward from the outside disk of the Sun. The second one occurs when it is inside the disk, while the third transpires when Venus starts to moves out of the disk. The final phase takes place when the planet becomes totally out of the Sun’s disk.
In the Philippines, the transit appeared on June 6 at 6:09 a.m. and lasted until 12:49 p.m.
The UST College of Science also conducted its own “public viewing” at the Main Building.
A 40-year-old astronomical telescope of the University was set up to encourage students to witness the rare astronomical phenomenon.
“It was also a treat [especially to the freshmen] because [the viewing] was presented during the first week of the school year,” said Daniel Vicario, a professor from the Mathematics and Physics department who initiated the viewing.
Experts say it is unadvisable to use the naked eye in viewing the transit or any other space phenomenon involving the Sun because direct exposure to its rays may cause temporary or permanent eye damage. They highly recommend the use of telescopes or binoculars with solar filters. with reports from Bernadette Nicolas
