Planetary system Current Affairs

Parker Solar Probe: NASA to launch Humanity’s first flight to Sun in July 2018

NASA’s will launch humanity’s first mission Parker Solar Probe (PSP) to the Sun in July 31, 2018. It is undergoing final preparations for its scheduled launch on board of NASA’s Delta IV Heavy launch vehicle from Kennedy Space Centre in Florida. After its launch, the probe will orbit directly through solar atmosphere — the corona — closer to surface than any human-made object has ever gone.

Parker Solar Probe mission

It is NASA’s first planned robotic spacecraft to study outer corona of Sun. It has been designed and built by Johns Hopkins University Applied Physics Laboratory. It is named after solar astrophysicist Eugene Parker, first spacecraft of NASA to be named after living person.

The spacecraft is designed to endure harsh environment near Sun, by approaching within 8.5 solar radii (5.9 million kilometers) to ‘surface’ (photosphere) of Sun where incident solar intensity is approximately 520 times intensity at Earth orbit.

The probe will be fitted with thermal protection system (TPS) or heat shield made of reinforced carbon-carbon composite that will allow it to survive temperatures in Sun’s corona. It main systems and scientific instruments are located in central portion of shield’s shadow, where direct radiation from Sun is fully blocked.

The primary power for mission is dual system of solar panels (photovoltaic array). Secondary source consists of much smaller secondary array power that uses pumped-fluid cooling to maintain operating temperature.

Scientific goals of PSP

  • Determine structure and dynamics of magnetic fields at sources of solar wind.
  • Trace flow of energy that heats corona and accelerates solar wind.
  • Determine what mechanisms accelerate and transport energetic particles.
  • Explore dusty plasma near Sun and its influence on solar wind and energetic particle formation.

In its seven-year mission, PSP will explore Sun’s outer atmosphere and make critical observations to answer questions about physics of stars. Its data will also be useful in improving forecasts of major eruptions on Sun and subsequent space weather events that impact technology on Earth, as well as satellites and astronauts in space.

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Astronomers discover Venus-like planet orbiting a dim star Kepler-1649

Astronomers using NASA’s Kepler space telescope have discovered a Venus-like planet orbiting a dim star called Kepler-1649.

The newly found planet is one-fifth the diameter of our Sun and is only slightly larger than Earth. It is located 219 light years away from Earth.

Key Facts
  • The Venus-like planet tightly embraces its low-temperature star Kepler-1649 by encircling it every nine days.
  • The tight orbit around the star causes the flux of sunlight reaching it to be 2.3 times as great as the solar flux on Earth. For comparison, the solar flux on Venus is 1.9 times the terrestrial value (on earth).
  • The discovery will provide insight into the nature of planets encircling around M dwarf stars, by far the most common type in the universe.

About Venus

  • Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. It is named after the Roman goddess of love and beauty.
  • It is a terrestrial planet and is sometimes called Earth’s “sister planet” because of their similar size, mass, proximity to Sun, and bulk composition. It has no natural satellite.
  • But it is radically different from Earth in other respects. It has densest atmosphere of four terrestrial planets, consisting of more than 96% CO2. The atmospheric pressure at its planet’s surface is 92 times that of Earth.
  • Note: Venus is by far the hottest planet in the Solar System, with a mean surface temperature 462 °C even though Mercury is closer to the Sun.

About Kepler Space Telescope (KST)

  • KST is an unmanned space observatory launched in 2009 by National Aeronautics and Space Administration (NASA).
  • It is tasked with determining how commonly, Earth-like planets occur throughout the Milky Way galaxy.
  • KST works by observing a dimming in the light of a star, known as a transit, each time an orbiting planet passes in front of it.
  • It has been designed for a statistical mission and not to probe into the environmental conditions of planets that exist in the so-called Goldilocks zone (Habitable zone) of their stars.

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