Earth’s Halo

 Earth’s Halo

Since the first space missions in the 1950’s, the most famous of which was Sputnik’s launch into a low elliptical orbit by the USSR, 4 October 1957, humans have sent thousands of items into low or near orbit and many also into deep orbit. 

These range form very small satellites which circuit the Earth at about 400 km altitude, the largest of which is the ISS. The term "LEO region" is also used for the area of space below an altitude of 2,042 km (1,269 mi) above the mean radius of Earth

However some satellites are placed in “geo-stationary” orbit and are usually situated a lot further out, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 kilometres (22,236 miles) above Earth's equator and following the direction of Earth's rotation.

Some of these satellites are created for the benefit of all humans in every country. For example, we all benefit from mobile communications and navigational aids; builders of new constructions can locate the the construction’s precise starting point on any piece of Earth within millimetres using such satellite information.

However a very large percentage of all the satellites which have been launched are for military purposes. Every major nation uses many of these to serve its national interests.

Today I present this 2019 animation from the European Space Agency which shows items circling the Earth in what I call our “halo”. It’s our physical and electronic “signature” which would be visible to any space travellers or ET’s, so if ET is watching us then ET knows exactly what were are doing, precisely which level of ”sophistication” we have achieved.

In this the animation you will notice that the “halo” gets more dense as they reveal smaller objects, as indicated in the top right corner of the screen.

The animation includes “space junk” such as “dead” satellites which no longer function at all, or pieces of rocketry such as discarded heat shields and many other useless items. All these items, whether useful or not, are travelling at incredible speed (28,000 km/h or 17,000 mph) in this cloud I call our halo. Most of them travel in a “belt” moving from left of screen to the right of screen, but there are some which traverse our poles and some which use different orbits.  

Because of “gravity” they all tend to fall to Earth as we know from occasions in the past, e.g., the crash which occurred a few weeks ago in USA when a SpaceX  service rocket burnt up over USA. 

For me, the most incredible event was when “Skylab” scattered its pieces across our Australian outback about 1979… I was watching the Sky with very great interest at the time, wondering how many large chunks would make it to the surface  of the Earth without killing people or damaging property.

Just a small digression here, until now the Skylab space station is one of the larget items ever lifted into orbit in one piece, weighing about 100 tons. Most lifts these days are limited to about 1 ton. E.g.,  the “payload” for launching “Perseverance” last year was 1025 kg or 2,260 lb.

That’s only 1.13 US ton.

Skylab isn't the largest space station to orbit the Earth, it was the first, orbiting Earth from 1973 until 1979, it was just shy of 170,000 pounds. As the orbit of Skylab decayed earlier than the nine-year life expectancy, NASA lacked a plan to bring the station back to Earth. Instead, it crashed, with most of the station landing in the Indian Ocean but some debris hitting populated areas in western Australia.  

At about 356 feet by 240 feet, the International Space Station is larger than a football field. Weighing in at 450 tons the ISS easily beats the Russian Mir as well as Skylab as the largest space station yet built. The station wasn't launched at once, but was built as pressurized modules that were pieced together, finishing up in 2011. It includes solar panels for power and trusses for structural support. 

There are far too many satellites to record in this quick review. Suffice to say there are thousands of them and they travel at extremely high speed in a halo like cloud, always tending to fall to Earth if they don’t burn up on re-entry. The more important ones need to be “boosted” or pushed further out from time to time, e.g., about the ISS (from Forbes Magazine)

“But, remember that Sir Isaac said we needed to be high up to avoid the drag of the air, well even at 250 miles (400 km) there is still a tiny bit of air and it has a small decelerating effect on the ISS. The ISS loses up to 0.1 mph (5 cm/s) of velocity and 330 ft (100 meters) of altitude each day, because of the continual collisions with gas particles. 

To compensate for this, about once a month the ISS briefly fires its thrusters to regain the lost altitude.”

https://www.forbes.com/sites/quora/2018/04/18/what-prevents-the-iss-from-falling-out-of-orbit/?sh=5254cb2a7b88

So the Earth has a halo, actually it's a two-fold halo, both physical and electrical: the physical part is made up of various metallic compounds, the electronic component is comprised of trillions of radio signals which are sent back and forth to Earth and also out into deep space. I wonder if these signals could ever be calculated as in the animation of the material objects.

There are many ambitious plans to “clean up” some of the space junk we have put out there but I’m extremely doubtful that these ventures will ever achieve any significant reduction. This is quite frightening as every day brings new launches by many new nations sending a great deal more satellite and rocketry material into space.

Should we be so concerned?

pt