A date with Mercury over Sun - Mercury Transits on Monday, 9 th May 2016

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2 A date with Mercury over Sun - Mercury Transits on Monday, 9 th May 2016 A rare celestial event to explore the inner planet Astronomy teaches us to look upwards. It is the study and understanding of the universe beyond the planet Earth. It is impossible for anyone to rival the magnificence of universe. The astronomical bodies viz., Planets, Comets, Asteroids, Meteors, Nebulae, Stars and celestial manifestations like eclipses, occultations, transits, oppositions and planetary conjunctions absolutely reveal the magnanimity of astronomy. Come 9 th May this year, It s a Monday and it s the day of Transit of Mercury over the Sun. It would be a rare celestial spectacular event to be seen on our sky that will definitely creates excitement and curiosity to explore more. A Transit is principally the passage of a celestial object (usually this presents a smaller angular size) in front of another object, presents a much larger angular size, as seen from Earth. In other words, a small celestial object will pass in front of a huge celestial object. On 9 th May, it is possible to witness the planet Mercury passing in front of the massive and dazzling heavenly object Sun. Passages of Mercury in front of the Sun, or "Mercury Transits" in astronomical terminology, are comparatively rare events, due to the different orbital inclinations of the Earth and Mercury as they move around the Sun. On Monday, May 9, 2016 Mercury will transit the Sun for the first time since The transit or passage of a planet across the face of the Sun is a relatively rare occurrence. As seen from Earth, only transits of Mercury and Venus are possible. During a transit, Mercury is seen as a tiny black dot moving slowly in an East-to-West direction across the Sun. The 2016 transit commences on 9 th May at 4.30 pm and ends later during the midnight. The total duration is therefore about 7½ hours. As per our sky, the transit of Mercury will be visible from 4.30 pm till the sun set at 7.11 pm. Till 6.30 pm, we can see the 1/4 th of the transit process. The planet Mercury crosses the Sun in a North-east to South-west direction, as opposed to a South-east to North-west direction at the previous transit in November This is because May and November transits of Mercury are viewed from opposite sides of the Earth's orbit, Mercury being seen descending (moving North to South) during May transits and ascending (moving South to North) during November transits. There are about 13 Mercury transits each century and they follow in time intervals of approximately 13, 7, 10 and 3 years. The most recent one took place in November 8, After 2016, the next two Mercury transits will take place on 11 th November 2019 and 13 th November The 11 th November 2019 transit will not be visible to India. The disk of Mercury is very small and will be very difficult to see. Bathed in intense sunlight, this small, hot planet moves around the Sun in an elliptical orbit at a mean distance of only 58

3 million km, much closer to the Sun than other inner planet, Venus (108 million km) and the Earth (150 million km). In order for a Mercury transit to happen, the planet must be located directly between the Earth and the Sun and also near one of the two points in its orbit where Mercury's orbital plane intersects that of the Earth. We then face the dark side of Mercury - the hemisphere that is not illuminated by the Sun - and see it as a small dark spot moving across the bright solar disk. A powerful telescope is needed to observe this event and to show clearly how Mercury moves across the solar disk. During the transit, Mercury will only block 1/20,000th of the Sun's light. The German astronomer Johannes Kepler ( ) was the first person to predict a Mercury transit event, although he did not observe one himself. His prediction of a transit on November 7th 1631 enabled the French mathematician and astronomer Pierre Gassendi ( ) to observe it, in the year following Kepler's death. Observations of the transit The Transit of Mercury cannot be observed with naked eye - this would also be extremely dangerous because the enormous brightness of the Sun will cause total blindness in a fraction of a second. Observations can only be made by means of telescopes which project the solar image onto a white screen. Solar filters can be used to have a glimpse of the transit. Other hands on projects including pin-hole camera can be used to project the transit picture for observation. Gujarat Science City will arrange special events on this occasion. Gujarat Council on Science & Technology (GUJCOST) has also arranges public viewing programmes at its Community Science Centers and Science Club Schools at each districts in the State. As the programme doesn't happen often, the Science City and Community Science Centres across the State will guide you to "spot the spot" Mercury's silhouette as the innermost planet crosses the Sun's disk. GUJCOST is organizing training workshops for science educators, communicators and amateur astronomers to orient them about the upcoming Transit of Mercury. Special activity modules have been designed to explore and understanding the inner planet and its behaviour. - Dr. Narottam Sahoo Advisor, GUJCOST

4 Transit of Mercury May 9, 2016 Monday A unique Science Discovery Programme Gujarat Council of Science City Gujarat Council on Science & Technology Dept of Science & Technology, Govt of Gujarat

5 Transit of Mercury Astronomy teach us to look upwards. It is the study and understanding of the universe beyond the planet Earth. It is impossible for anyone to rival the magnificence of universe. The astronomical bodies viz., Planets, Comets, Asteroids, Meteors, Nebulae, Stars and celestial manifestations like eclipses, occultations, transits, oppositions and planetary conjunctions absolutely reveal lthe magnanimity it of astronomy.

6 Mercury: The wandering star

7 Mercury: The wandering star Named after Mercury, the Roman god of commerce and delivering messages His name comes from the Latin word "mercari" meaning to deal or trade. The planet was named Mercury because it appeared to move faster in the sky than any other planet. We now know that this was because of its small orbit.

8 Mercury: The wandering star Average distance from Sun: Length of Year: AU (57,910, km/35,980, mi) 88 days Rotation oa o period: days Mean orbital velocity: 48 km/s (30 mi/s) Inclination of axis: 2 Average temperature: Diameter: 800 F (427 C) day -300 F (-183 C) night 4,878 km (3,031 mi) Number of observed satellites: 0 Magnetic field weak

9 Mercury: The wandering star Mercury is one of the five planets known to the ancients. They called these planets "wandering stars". Mercury may be seen as an evening "star" near where the sun has set, or as a morning "star" " near where the sun will rise. The ancient Greeks called the evening star Hermes and the morning star Apollo, believing them to be different objects. The planet is named for Mercury, the Roman messenger of the gods.

10 Mercury: The wandering star Mercury is not much bigger than our Moon. It is the smallest planet. It is so close to the Sun that it can be seen only in the twilight sky of the Earth. The hazy atmosphere near the horizon on Earth spoils the view of Mercury for ground-based telescopes. Closest distance to Earth 77 million km Farthest distance from Earth 222 million km Mass 3.3 X kg Density 5.43 g/cm 3 Earth-based telescopic photo of Mercury taken from Catalina Observatory 1.5 meter (61 inch) telescope.

11 EARTH MERCURY MOON Mercury s diameter is 4,880 km. That s 40% smaller than Earth and 40% larger than the moon

12 Mercury s density is similar to that of Earth s at gm/cm^3 Rocky mantle Mercury s core is 75% of its mass, and consists of iron and molten lava Scientists think Scientists think Mercury s dipolar magnetic field is produced by its partially molten core.

13 Mercury Orbital Facts Until 1965, scientists thought that the same side of Mercury always faced the Sun. Mercury takes only 88 Earth days to complete one orbit Rotates slowly, once every 59 Earth days. This means that it rotates precisely three times for every two orbits

14 More Orbital Facts orbits the Sun in a highly elliptical orbit at about one third of the Sun-Earth distance. 46 million kilometers from the Sun at perihelion (closest), 70 million kilometers away at aphelion (furthest). Rotates vertically, so Mercury does not have opposite seasons in each hemisphere like Earth does. Seasonal temperatures vary with distance from the sun. Extremely hot days and very cold nights. Mercury has very y y y g y y little atmosphere so the surface cools down rapidly on the night side.

15 Mercury s Atmosphere Mercury has almost no atmosphere and no water. The trace gases (oxygen, sodium, helium) that are there are made up of atoms or ions blasted off its surface by the solar wind. Mercury's extreme surface temperature enhances the escape of these volatile atoms into space. No erosion from wind or water. Might have water ice at its north and south poles inside craters where the sun cannot reach. Meteorites do not burn up due to friction because there is no atmosphere.

16 Mercury Transit 2016 There are about 13 Mercury transits each century and they follow in time intervals of approximately 13, 7, 10 and 3 years. The most recent one took place in November 8, 2006.

17 Facts of Mercury Transit 2016 During transit period, Mercury will only block 1/20,000th of the Sun's light. The German astronomer Johannes Kepler ( ) 1630) was the first person to predict a Mercury transit event, although he did not observe one himself. His prediction of a transit on November 7th 1631 enabled the French mathematician and astronomer Pierre Gassendi ( ) to observe it, in the year following Kepler's death.

18 Mercury Transit 2016 visibility

19 Transit of Mercury Image of May 7, 2003 Mercury Transit was taken by NASA/ESA's SOHO (Solar & Heliospheric Observatory)

20 Transit of Mercury Transit of Mercury on November 8,2006. Sunspot #923, which is just below the equator at tthe left-hand fth side, is much bigger than Mercury is. Two more sunspots at the righthand side at the equator. Mercury appears as a small black dot in the lower middle of fthe solar disk.

21 Transit of Mercury Next transit: May 9, 2016

22 Mercury Transit 2016 The total duration of the transit will be about 7½ hours.

23 Mercury Transit 2016 ANIMATION

24 Mercury Transit 2016

25 Mercury Transit 2016

26 Mercury Transit 2016

27 Have a safe and pleasant viewing! THANK YOU!