What kinds of space rays are detectable on earth

  • Context: High School 
  • Thread starter Thread starter Imparcticle
  • Start date Start date
  • Tags Tags
    Earth Rays Space
Click For Summary

Discussion Overview

The discussion revolves around the types of rays emitted from various sources in space that can be detected on the surface of Earth. It encompasses topics related to electromagnetic radiation, cosmic rays, and neutrinos, as well as the limitations imposed by the Earth's atmosphere on astronomical observations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants note that electromagnetic radiation detectable on Earth includes radio waves, microwaves, infrared (low frequency), and visible light, while higher frequency infrared and visible light are blocked by the atmosphere.
  • Neutrinos are mentioned as particles that can pass through the atmosphere with minimal interaction, making them detectable on Earth.
  • Cosmic rays are discussed, with a distinction made between primary cosmic rays, which rarely reach the Earth's surface, and secondary cosmic rays, which are generated by collisions of primary cosmic rays with the atmosphere.
  • One participant highlights the use of probes and orbital observatories to detect phenomena not visible from Earth due to atmospheric interference.
  • There is mention of the composition of cosmic rays, including particles like protons and iron nuclei, as well as gamma rays and neutrinos, with a note that cosmic rays typically do not include neutrinos.
  • Another participant explains that cosmic rays create air showers when they collide with atmospheric nuclei, generating secondary particles that can be observed on the surface.
  • The impact of galactic magnetic fields on charged cosmic ray particles is discussed, indicating that their original direction is lost by the time they are detected on Earth.
  • Gamma rays are noted to be neutral and not affected by magnetic fields, but they do not reach the Earth's surface and are detected through Cherenkov radiation.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the types of rays detectable on Earth and the mechanisms of detection, indicating that the discussion remains unresolved with no clear consensus.

Contextual Notes

Limitations include the dependence on atmospheric conditions for detection, the uncertainty surrounding the existence of certain particles, and the unresolved nature of the effects of gravity waves.

Imparcticle
Messages
572
Reaction score
4
What kinds of rays are emitted from various sources in space and are detectable on the surface of earth?
 
Astronomy news on Phys.org
If you refer to electromagnetic radiation, the answer is: the major part of radio, all microwaves, and also infrared of low frequency, and also obviously, the visible range. IR of high frequency and higher frequencies than the visible are all blocked by the atmosphere, as well as radio of very low frequency. The fact that some radio waves can reach the surface is useful, so we can have monstruous radiotelescopes like that existing in Arecibo, Puerto Rico
Neutrinos can pass freely through the atmosphere, as they practically don't interact with matter.
There are also cosmic rays. Primary cosmic rays habitually don't reach Earth's surface (though a few achieve it); practically all secondary cosmic rays reach Earth surface (secondary cosmic rays don't come from any extraterrestial source, they are created by the collission of primary cosmic rays with the atmosphere)
 
Last edited:
The Earth's atmosphere is not very astronomy friendly, albeit even astronomers prefer living on a planet that has an atmosphere. There are a number of probes and orbital 'observatories' [eg, Hubble telescope] used to scope out stuff not visible, or poorly visible from earth. There may also be other particles that we do not yet know exist because they rarely interact with ordinary matter [like neutrinos, which we knew must exist well before we actually detected them] or interact so weakly their effects are very difficult to detect [like gravity waves].
 
meteor and Chronos have given good summaries.

Just to add a few words on 'cosmic rays': these are comprised of particles (e.g. protons, Fe nuclei), EM (gammas), and neutrinos (tho' 'cosmic rays' doesn't usually include neutrinos). As meteor said, few, if any, particles reach the Earth's surface - they collide with nuclei of oxygen, nitrogen, etc (in the upper atmosphere) and generate 'air showers', which are cascades of secondary particles. These air showers are observable down here, under all the air, and there are a number of very powerful 'cosmic ray observatories' on (or under) the Earth's surface. However, as most cosmic ray particles are charged, they are affected by the galactic magnetic fields, so all information about their original direction is lost by the time we 'see' them (we can tell from which direction they were coming when they hit the atmosphere, but not where they started out).

The gammas, being neutral, aren't affected by magnetic fields. However, they don't reach the surface of the Earth either - they are detected by Cherenkov radiation, which arises because the speed of light in air is lower than that in vacuo. There also several such 'TeV gamma cosmic ray telescopes' (the 'TeV' refers to the energy of the gammas - the 'T' means 10^12, i.e. 1,000 billion).
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 12 ·
Replies
12
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 29 ·
Replies
29
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K
Replies
2
Views
2K