Space weather

Space weather, influenced by solar phenomena, has raised concerns about the vulnerability of LEO satellites, exemplified by the recent loss of Starlink satellites.

What is causing loss of satellites?

• A team from the IISER, Kolkata, in collaboration with NASA and Predictive Sciences Inc., was to determine the relationship between prevailing spaceweather conditions at LEO and the loss of Starlink satellites.
• The analysis conducted revealed that the loss of the satellites was not attributable to a single factor but rather a combination of several.
• These factors included the prevailing space weather conditions at the time, the insertion of the satellites into a relatively high-density LEO, and the possibility of enhanced drag due to orientation changes of the satellites.

About Spaceweather:

• Spaceweather are conditions and disturbances in space, particularly those influenced by the Sun, that can affect technological systems and infrastructure both in space and on Earth.
• Space weather is primarily caused by solar storm phenomena, which include: solar flares, solar particle events, coronal mass ejections (CMEs), and solar wind.
  • The Sun emits a constant stream of gas and charged particles into space known as the solar wind, originating from its hot outer atmosphere, the corona.
  • A solar flare is an intense burst of radiation coming from the release of magnetic energy associated with sunspots.
  • CMEs are large expulsions of plasma and magnetic field from the Sun’s corona.

How space weather interacts with earth’s atmosphere?

• Earth possesses a magnetic field, an area of magnetic force activity, and is enveloped by a layer of gases known as the atmosphere.
• The magnetic field and atmosphere act like a shield, protecting earth from the majority of the solar wind blast.
• The majority of charged particles collide with Earth’s protective shield and bypass it.
• These particles compress and distort the side of the magnetic field facing the Sun, while the opposite side of the magnetic field extends into a long, trailing tail.
• Occasionally, charged particles manage to penetrate Earth’s shield.
• When these particles collide with the atmosphere, they create luminous displays known as auroras.

Impact of space weather on earth:

Radio Blackouts:

• Solar flares emit X-rays, among other electromagnetic energy.
• Increased X-ray emissions can scatter radio waves, causing radio blackouts on Earth due to disruptions in the ionosphere.

Solar Radiation Storms:

• Solar radiation storms result from solar flares and coronal mass ejections.
• These storms involve large bursts of protons and other particles from the Sun, which can elevate radiation levels near Earth to harmful levels.
• This poses health risks for astronauts at the International Space Station and, occasionally, for airline travelers in polar regions.

Geomagnetic Storms:

• A large coronal mass ejection can cause a strong gust of solar wind to reach Earth, transferring energy to Earth’s magnetic field and causing a geomagnetic storm.
• These storms can create intense currents in Earth’s magnetosphere and cause the ionosphere and upper thermosphere to heat up.
• The most common effect on Earth is spectacular auroras, but they can also disrupt radio signals and navigation systems, create drag for low-orbiting satellites, and harm power grids.

About Starlink:

• Starlink is a satellite internet constellation that provides high-speed internet to over 70 countries.
• It is the first and largest satellite constellation to use low Earth orbit, which allows it to provide internet that supports streaming, gaming, and video calls.
• Starlink is operated by Starlink Services, LLC, a subsidiary of SpaceX, an American aerospace company.
• SpaceX has been launching Starlink satellites since 2019.

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