TOUR OUR INNER SOLAR SYTEM
Explore the rock planets of our local area.
A cold cloud of gas-and-dust buried deep inside one of the Milky Way Galaxy’s spiral arms began to fall approximately 4.5 billion year ago. There gravity started to work its magic. The cloud began shrinking and fracturing; one of these fragments was to become the Sun and the rest the solar system.
Gravity continued to compress the solar nubula and so the central region that would become Sun began to absorb the majority of the material.
However, because the nebula rotated, not all of it could fall into the proto Sun being forged at its center. Instead, some of it formed an annul that would eventually condense to the planets and other smaller members the solar system.
THE SOUN
This stage of the solar system saw the proto-Sun continue to contract, and as it did, it grew warmer. This process continued until the object’s central temperature rose enough to spark nuclear fusion. The pressure created by the nuclear reactions caused heat that counteracted gravity. Thus, the object became stable star we now call the Sun
The Sun continues to produce its energy in the exact same way. At temperatures of 27 million degrees Fahrenheit (15,000,000 degrees Celsius), the core contains positively charged protons. These nuclei are hydrogen atoms’ nuclei. They can overcome mutual repulsion to fuse together and create helium.
Despite being a giant ball of gas, the Sun seems to have a sharp edge. The Sun’s energy radiates from only a few hundred mile thick, as opposed to its overall radius, which is 435,000 miles (700,000.km).
The photosphere is a thin layer of air that is called by Astronomers. It has an approximate temperature of 10,000 F (5,500 C). The photosphere is the lowest layer of the Sun’s atmosphere. Below it is the slightly warmer chromosphere. This thin layer measures between 1,000-2,000 miles thick. The corona lies above the chromosphere, which is a superheated region with temperatures that can rise to millions upon millions of degrees. The Sun’s gravity can’t hold onto this hot gas and the outer atmosphere basically boils off into the vacuum of space. This “solar wind”, permeates all of the solar system.
Sunspots are some of the most visible features on the Sun. These dark splotches can be attributed to the photosphere. Sunspots, which glow at temperatures around 1,500 Kelvins (2.700 degrees F) below the photosphere, don’t produce as much light than the surrounding photosphere.
Sunspots may last for anywhere from a few days to a few weeks. Sunspots are also known to cluster. Some sunspots may have more than 100 individual spots. These large groups are magnetized and can produce flares, some of the biggest explosions in the solar systems. A typical flare can last between five and ten minutes and release as much as a million hydrogen bombs. The largest flares last up to an hour and can produce enough energy for the United States (at its current electric consumption rate) to power it for 100,000 years.
Studies of sunspots in the past two centuries have shown that there is a variation in the number of spots. From sunspot maximum up to minimum, this solar cycle takes approximately 11 years.
Since antiquity, Mercury’s existence has been known by observers. It is visible to the naked eyes along with Venus Mars Jupiter Saturn and Saturn. Mercury, named after the Roman god for trade, takes only 88 Earth days orbiting the Sun. But, the day it takes to orbit the Sun (from sunrise to sunset) is twice that — it takes 176 Earth Days.
This is the innermost planet, and it’s also the smallest. It is about 2.6 times smaller then Earth and holds about 5.5 per cent of the planet’s weight. Mercury is also the densest planet, right after Earth.
Mercury, like other terrestrial planets has a rock composition. Its core is responsible for over 40% of its mass. Comparing this to Earth, where the core makes up only around 16 percent of its total weight. Astronomers believe the core has a high mass because it is mostly iron.
Mercury’s 38 percent distance from Earth might lead you to believe that Mercury would never be hot because of its proximity to the Sun. Mercury has almost no atmosphere. This means that while Mercury’s side faces the Sun is scorching hot at 800 F (430 C), its dark side can drop down to -300 F or -180 C.
Scientists detected hints ice in permanent shadowed areas at the planet’s poles using radar. How can ice be found on a planet so near to the Sun. Mercury’s orbit is almost straight up and downward, but Earth’s axis tilts at 23.5 degrees to the ecliptic. The Sun doesn’t shine on the innermost poles of planets. Also, the bottoms of craters at both the north and south poles are still shadowed (and therefore cold).
It is odd that this inner planet also has small magnetic fields. It is the only other terrestrial planet, besides Earth, to have a global field. Although scientists believe the planet’s magnetic fields are caused by liquid magma being moved outside of Earth’s solid core, they don’t know what is causing it to be created by Mercury. It would not be surprising that Mercury has a molten center, since it should have cooled billions years ago.