Showing posts with label Planets. Show all posts
Showing posts with label Planets. Show all posts

Monday, September 19, 2011

40 Amazing and Interesting Scientific Facts About the Planet Mercury

Mercury is the closest planet to the sun in the solar system. Here are some scientific and interesting facts about this planet.

1.) Mercury was named for the fleet-footed messenger of the gods in Roman mythology – the equivalent of the Greek’s Hermes.


2.) Mercury is the first planet in distance from the Sun in the solar system. It is the smallest of the 8 planets.

3.) This planet is the smallest of the rocky or terrestrial planets. The others are Venus, Earth, and Mars.

4.) Mercury is the only rocky planet other than Earth to have a global magnetic field, which is about 1% as strong as Earth’s.

5.) Like Venus, Mercury has no moons of its own.



6.) Although it is the nearest planet to the Sun, it is only the second hottest planet. Venus is the hottest.

7.) Mercury circles the Sun every 88 Earth days at an average distance of 58 million km and takes 59 days to turns on its axis.

8.) Mercury’s diameter is 4,879 km, about 40% the diameter of Earth or about 40% wider than the Moon.

9.) Mercury’s volume and mass are about one-eighteenth that of Earth.

10.) Mercury’s mean density, 5.4 g/cm³, is nearly as great as that of Earth and is higher than that of any of the other planets.

11.) The force of gravity on the planet’s surface is about 1/3 of that on Earth’s surface or about twice the surface gravity on the Moon and about the same as the surface gravity on Mars.

12.) Jupiter’s moon Ganymede and Saturn’s moon Titan are larger than Mercury but are much less dense.

13.) Mercury orbits the Sun every 87.97 Earth days at an average distance of approximately 58 million km.

14.) Mercury’s orbit is highly elliptical and ranges from 46 million km at its nearest point to the Sun (perihelion) to 69.8 million km at its farthest point (aphelion).

15.) As a result, sunlight is over 2.3 times stronger at perihelion than at aphelion.



16.) At a single orbit, Mercury receives as much as 11 times the intensity of sunlight that Earth does to a minimum of about 4.5 times.

17.) Mercury’s orbital velocity is also about 46 percent faster at perihelion than at aphelion. The planet’s orbit is tilted 7 degrees to the plane in which Earth orbits around the Sun.

18.) When viewed from North Pole. Mercury turns counterclockwise (west to east) like Earth and most other planets.

19.) Earth’s axis is tilted 23.5° while Mercury’s axis is almost perfectly vertical. Because its axis is vertical, like Venus, Mercury does not have seasons.

20.) Mercury rotates only once every 58.65 days, 2/3 of its period of revolution around the Sun.

21.) A complete solar day on Mercury lasts 175.84 Earth days, or two of Mercury’s years, and a night and a day at the equator each last one Mercurian year or 87.97 Earth days.

22.) Mercury preserves a record of a violent early period when asteroids, comets, and other debris bombarded the newly formed planets.

23.) The craters on Mercury are shallower than those on the Moon.

24.) The largest geological feature on Mercury is the Caloris Basin. It is the result of a massive ancient impact.

25.) Mercury’s surface is crisscrossed by long escarpments or cliffs.



26.) Mercury is a poor reflector of sunlight because its surface consists of dark, dry soil called regolith created by micrometeorite impacts over billions of years.

27.) The planet’s albedo, or the amount of sunlight it reflects, is only about 12 percent, about the same as our Moon.

28.)  Surface temperatures on Mercury can be as hot as 650°C.

29.) Mercury’s side facing the Sun gets very hot—up to 450°C—while the side facing away quickly cools to frigid temperatures, -183°.

30.) The floors of craters at the north and south poles receive very little sunlight and always remain extremely cold—about -200°C.

 31.) Mercury’s equatorial region experiences extreme changes, reaching 450°C at perihelion when facing the Sun—hot enough to melt zinc.

32.) In 1991 powerful radio telescopes on Earth revealed signs of possible deposits of ice in the polar regions of Mercury.

33.) These ice deposits occur in areas where sunlight never falls, such as crater bottoms near both of the planet’s poles.

 34.) The ice on Mercury likely comes from comets or water-bearing meteorites that have hit Mercury over the planet’s history up through the present.

35.) Scientists use a technique called spectroscopy to conduct studies of the light that Mercury reflects.



36.) These studies indicate that planet has only an extremely thin atmosphere, containing sodium and potassium.

37.) The first up-close study of Mercury came with National Aeronautics and Space Administration (NASA)’s Mariner 10 spacecraft, which passed Mercury twice in 1974 and once in 1975.

38.) It sent back pictures of a moonlike, crater-pocked surface. The spacecraft also detected a magnetic field and provided data about the planet’s density and some of its surface chemistry.

39.) In 2004, NASA launched a much more ambitious mission to Mercury – the so-called MESSENGER- MErcury Surface, Space ENvironment, GEochemistry, and Ranging.

40.) MESSENGER is set to enter orbit around Mercury in 2011. The first orbital image of Mercury was obtained on March 29, 2011.

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Friday, September 16, 2011

35+ Amazing and Interesting Scientific Facts About the Planet Venus

Venus is the second planet from the sun in our solar system. Here are some important, scientific and interesting facts about this planet.

1.) The planet was named for Venus, the Roman goddess of beauty – the equivalent of the Greek’s Aphrodite.

2.) Although Venus is second only in distance from the Sun, it is the hottest planet in the solar system

3.) Venus is the brightest object in the sky except for the Sun and the Moon.

4.) Venus is unique because it also lacks a magnetic field and a moon.

5.) The hellish surface of Venus has broiling temperatures that make rocks glow red.



6.) Venus is the nearest planet to Earth in distance at about 41 million km away at its closest approach.

7.) Venus is nearly the same size as Earth hence; they are sometimes called twin or sister planets.

8.) Venus takes 243 days to rotate on its axis in the opposite direction.

9.) Venus circles the Sun once every 224.7 days or a little over seven months in a counterclockwise direction, the same direction as the other planets in the solar system at a distance of 108 million km.

10.) Venus is often called the “morning star” when it appears in the east at sunrise and the “evening star” when it is in the west at sunset.

11.) In ancient times the morning star is called Phosphorus, Eosphoros, or Lucifer and the evening star was called Hesperus.

12.) Venus’ axis is nearly vertical and its orbit is nearly circular so it does not experience seasons the way Earth and Mars do.

13.) Venus rotates very slowly, once every 243 Earth days. Venus’s rotation is retrograde, which means that the planet turns clockwise (from east to west) as seen looking down on its north pole.

14.) Earth and most other planets turn counterclockwise (from west to east).

15.) A full solar day on Venus—the time when the Sun next passes the noon point in the sky—is 116.8 days long.



16.) Viewed from a spot on the equator of Venus, the Sun rises in the west and takes 58.4 days to cross the sky until it sets in the east. Night also lasts 58.4 days.

17.) The atmosphere of planet Venus consists of 97 percent carbon dioxide (CO2) and is so thick that the surface pressure is 96 bars. The earth is 1 bar only.

18.) Venus’ surface temperature is extremely hot which is about 462°C or hot enough to melt lead.

19.) Venus is only slightly smaller and less dense than Earth. Its radius is 6,052 km and its average density is 5.2 g/cm³.

20.) The surface of Venus is primarily a rolling plain interrupted by two continent-sized highland areas named Ishtar Terra and Aphrodite Terra.

21.) The Magellan spacecraft has revealed huge volcanoes, large solidified lava flows, and a large array of meteorite craters.

22.) The largest impact crater in Venus is almost 300 km across—the smallest about 5 km.

23.) There is also evidence that a great deal of tectonic activity has taken place on Venus, at least in the past.

24.) Evidence of tectonic activity includes ridges, canyons, a trough-like depression that extends across 1,400 km of the surface, and a gigantic volcanic cone whose base is more than 700 km wide.

25.) Because the size and density of Venus and Earth are so similar, scientists think the two planets originated in the same way.



26.) Venus, Earth and other planets on the Solar System were formed about 4.6 billion years ago out of the spinning disk of dust and debris that surrounded the newborn Sun.

27.) The first flyby sent to Venus was that of Mariner 2 of the US in 1962, followed by Mariner 5 in 1967 and Mariner 10 in 1974.

28.) The former Union of Soviet Socialist Republics sent several flybys or orbiters to planet Venus successfully reached the planet’s surface.

29.) In 2005, the European Space Agency (ESA) launched the Venus Express spacecraft on a mission to Venus and started orbiting Venus in 2006.

30.) The Venus Express also carried the first infrared instrument designed to study the planet’s surface at infrared wavelengths, making it possible to detect active volcanoes if they exist.

31.) The stifling atmosphere in Venus is so dense that even a slow breeze would feel like a tremendous gust.

32.) If humans can be in Venus, the Sun would be only faintly visible through the dense clouds and the entire surface would appear yellow-orange during day time.

33.) During nighttime in Venus, it would not be dark – the entire rocky landscape would glow a dull red like the burner on an electric stove.

34.) If the concept of hell is true, Venus may be the closest thing in the solar system comparable to hell.

35.) A human in Venus would weigh about the same as on Earth.



36.) The size comparison of terrestrial planets from left to right: Mercury, Venus, Earth and Mars.

37.) The planet’s surface gravity is nine-tenths as strong as surface gravity on Earth; an object that weighs 10 kg on Earth would weigh 9 kg on Venus.

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