Curtained Skies
What is an Aurora?
The Aurora is a series of spacecraft launched by the United States to study the Sun. The first two, Pioneer 10 and 11, were established in 1972; they are now beyond Pluto’s orbit. A third was planned for launch in 1978 but never flew. Two more missions have been proposed: an unmanned probe that could reach Jupiter while another would carry a crewed craft to Mars.
What is the Etymology behind Aurora?
The word “aurora” comes from Latin for dawn, which was borrowed from Greek ἀύρας meaning ‘dawn’. However, there is no evidence for such an etymological connection.
What is the history of the northern lights?
Auroras were first observed by ancient Chinese astronomers who called them “the Moon shining through clouds.” It was not until 1859, when British astronomer Richard Carrington discovered an enormous solar storm, that he realized these mysterious flashes could be caused by charged particles streaming out of the Sun.
In 1912, American astrophysicist Edward Emerson Barnard coined the term “northern lights” to describe the greenish glow seen above the Arctic Circle during the winter months.
Where does the Occurrence of Aurora occur?
In general, an oval auroral forms over any magnetic pole when sufficient energy is available for particle precipitation. This can occur during increased geomagnetic activity such as substorms, coronal mass ejections, flares, etc. When these energetic events occur near the poles, they may cause large numbers of particles to be accelerated towards the earth’s surface by the Lorentz force.
What are the Different Forms of Aurora?
Auroras are generally caused by energetic particles accelerated along open magnetic field lines. They are produced by collisions between ions and neutral atoms in the mesosphere and stratosphere. When the energy density of the incoming cosmic ray flux exceeds a critical value, the process of charge separation occurs. Electrons gain enough kinetic energy to escape their parent atom and become free charges.
What are the Colors and wavelengths of auroral light?
In general, the intensity of the aurora depends upon several factors, among them the density of free electrons in the upper layers of the atmosphere, the magnitude of the electric current flowing along the earth’s surface, and the rate of precipitation of energetic ions onto the ground. It is believed that the aurora occurs because of collisions between electrified atoms and molecules in the upper atmosphere. When the atom loses energy due to a clash with another molecule, it emits radiation.
How does the Aurora Change with time?
In general, the intensity of the aurora depends upon several factors: the density of free electrons in the upper atmosphere, the magnitude of the electric current flowing along the earth’s surface, the rate of precipitation of energetic ions onto the ground, and the speed of the incoming solar wind. For instance, auroras tend to be stronger where the number of free electrons is higher and weaker where the flow of currents is faster.
What is the Other auroral radiation?
Energetic particles generally cause auroras to accelerate along open field lines in the magnetotail. They originate in the dayside magnetopause, where reconnection occurs between the magneto-sheath flow and the closed magnetotail current sheet. Particles are then energized further by compression waves generated by the interaction of the fast-flowing magneto-sheath ions with the slower moving magnetotail electrons.
Where can we see the Aurora?
Yes! You can view the Aurora Borealis from almost any location without direct sunlight. It will appear as an eerie glow above the horizon, usually appearing first around midnight local time.
How do you see the northern lights?
Look southward as far away from city lights as possible to view the northern lights. If your location doesn’t offer clear skies, try looking west instead. You’ll need binoculars or a telescope to spot the auroras. However, if you’re lucky enough to be able to watch the northern lights without equipment, don’t worry — you won’t miss out on anything special.