The solar system comprises various celestial objects bound together by the gravitational pull of the Sun. Here are the primary components:

1. The Sun
   • The central star and the largest object in the solar system.
   • It provides energy and light essential for life on Earth.
   • Composed mostly of hydrogen and helium, undergoing nuclear fusion.
2. Planets
   • Terrestrial (Rocky) Planets: Mercury, Venus, Earth, and Mars.
     • Composed of rock and metal.
     • Smaller and have solid surfaces.
   • Gas Giants: Jupiter and Saturn.
     • Composed mostly of hydrogen and helium.
     • Larger and lack a solid surface.
   • Ice Giants: Uranus and Neptune.
     • Composed of water, ammonia, and methane ices, along with hydrogen and helium.
3. Dwarf Planets
   • Examples: Pluto, Ceres, Eris, Haumea, and Makemake.
   • Smaller than planets and orbit the Sun.
   • Do not clear their orbital path of debris.
4. Moons (Natural Satellites)
   • Over 200 moons orbit planets in the solar system.
   • Notable examples: Earth’s Moon, Jupiter’s Ganymede (largest moon), and Saturn’s Titan.
5. Asteroids
   • Rocky bodies, mostly found in the Asteroid Belt between Mars and Jupiter.
   • Examples: Vesta and Ceres (also a dwarf planet).
6. Comets
   • Icy bodies that develop tails when they approach the Sun.
   • Originate from regions like the Kuiper Belt and the Oort Cloud.
7. Meteoroids, Meteors, and Meteorites
   • Meteoroids: Small, rocky or metallic bodies in space.
   • Meteors: Meteoroids that burn up upon entering Earth’s atmosphere.
   • Meteorites: Meteoroids that reach Earth’s surface.
8. The Kuiper Belt
   • A region beyond Neptune filled with icy bodies and dwarf planets like Pluto.
9. The Oort Cloud
   • A theoretical, distant spherical shell of icy objects surrounding the solar system.
   • Believed to be the source of long-period comets.
10. Interplanetary Medium
    • The space between planets filled with dust, gas, and solar wind particles.

Each component plays a crucial role in the structure and dynamics of the solar system.

Artificial satellites orbit the Earth by balancing two forces: the satellite’s forward momentum and the gravitational pull of the Earth. Here’s how this works:

Key Principles of Satellite Orbits

1. Gravity: Earth’s gravity pulls the satellite toward its center. Without this force, the satellite would fly off into space.
2. Inertia: According to Newton’s first law of motion, an object in motion will stay in motion unless acted upon by an external force. The satellite’s inertia keeps it moving in a straight line.
3. Orbital Motion: When a satellite is launched, it is given a horizontal speed. The satellite moves forward due to its inertia, while gravity pulls it toward the Earth. The balance between these two forces causes the satellite to follow a curved path around the Earth, which is its orbit.

Types of Orbits

• Low Earth Orbit (LEO): These orbits are close to Earth, typically between 160 to 2,000 kilometers above the surface. Satellites in LEO, like the International Space Station (ISS), circle the Earth quickly, completing an orbit in about 90 minutes.
• Medium Earth Orbit (MEO): These orbits range from 2,000 to 35,786 kilometers. GPS satellites often use MEO.
• Geostationary Orbit (GEO): At about 35,786 kilometers above the equator, satellites in GEO orbit the Earth at the same rate that the Earth rotates. This makes them appear stationary relative to a point on the Earth, ideal for communication and weather satellites.
• Polar Orbit: These satellites pass over the Earth’s poles, allowing them to scan the entire surface over time. They are often used for Earth observation and weather monitoring.

Maintaining Orbits

Satellites are carefully launched at specific speeds and angles to ensure they reach and maintain their designated orbits. Occasionally, small onboard thrusters make adjustments to correct the satellite’s path and altitude, a process known as orbital station-keeping.

By maintaining the delicate balance between gravity and inertia, artificial satellites can stay in orbit around the Earth for many years, serving a variety of functions like communication, navigation, weather monitoring, and scientific research.

The key differences between RNA (Ribonucleic Acid) and DNA (Deoxyribonucleic Acid) are in their structure, function, and role in cellular processes:

1. Structure:

DNA:

Double-stranded helix.

Contains the sugar deoxyribose.

Has the bases adenine (A), thymine (T), cytosine (C), and guanine (G).

RNA:

Single-stranded.

Contains the sugar ribose.

Has the bases adenine (A), uracil (U) (instead of thymine), cytosine (C), and guanine (G).

2. Function:

DNA:

Stores and transmits genetic information.

Acts as a blueprint for the synthesis of proteins.

RNA:

Plays a role in protein synthesis.

Types of RNA include:

mRNA (messenger RNA): Carries genetic information from DNA to ribosomes.

tRNA (transfer RNA): Brings amino acids to ribosomes during protein synthesis.

rRNA (ribosomal RNA): Forms part of ribosomes.

3. Location:

DNA:

Found mainly in the nucleus of eukaryotic cells.

RNA:

Found both in the nucleus and the cytoplasm.

4. Stability:

DNA:

More stable due to its double-stranded structure and the presence of deoxyribose.

RNA:

Less stable and more prone to degradation because it is single-stranded and contains ribose.

5. Length:

DNA:

Longer and contains the entire genetic code of an organism.

RNA:

Shorter, typically a copy of a single gene or a set of instructions for one protein.

These differences enable DNA to serve as the long-term storage of genetic information, while RNA plays a crucial role in the synthesis of proteins and the regulation of gene expression.