Caption: Third place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (still images) The blurred motions of the aurora caught during the exposure time of this photograph beautifully illustrate its dynamic nature. While certain forms of aurorae, like homogeneous arcs and bands or diffuse glows, can remain static for hours, others, like rayed arcs or bands (also called "curtains"), can change within seconds in shape and brightness.
Credit: Emanuele Balboni/IAU OAE

Caption: First place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (still images) Aurorae are the result of ionisation and excitation processes in Earth's upper atmosphere, caused by charged particles from the solar wind or from coronal mass ejections. The different colours in an aurora display indicate the species of atmospheric atoms and molecules involved. The most common colour is a bright green, which, together with deep red, originates from atomic oxygen. Blue, purple and pink hues are much rarer and originate from molecular nitrogen. The reflection of the aurora in the water indicates the brightness of intense aurorae at higher latitudes.
Credit: Marco Migliardi on behalf of Associazione Astronomica Cortina/IAU OAE.

Caption: Taken with a smartphone at Cassidy Point, Yellowknife, Canada, on 24 March 2023, this stunning display captured the ethereal Northern Lights painting the night sky. The biting cold of -20°F (-29°C) set the stage for the vibrant hues of the Aurora Borealis, a celestial ballet created by collisions between charged solar particles and the Earth's atmosphere. The Earth’s magnetic field directs the charged particles towards the polar regions, where they interact with the various atoms and molecules in the atmosphere. This natural phenomenon transforms the sky into a canvas of radiant greens, pinks, and purples, casting a mesmerising glow above. The different colours of an aurora are determined by the gases in Earth’s atmosphere, the altitude where the aurora occurs, the density of the atmosphere, and the energy of the charged particles. In general, green is attributed to oxygen molecules, red is associated with high-altitude oxygen molecules, purple and blue are associated with hydrogen and helium, and pink aurorae are typically associated with nitrogen. Against this cosmic backdrop, the teepees of Aurora Village below provide a tranquil contrast to the celestial spectacle unfolding overhead. Preserving the pristine darkness of this location ensures the continued splendour of such awe-inspiring natural light shows.
Credit: Oanh Vuong/IAU OAE (CC BY 4.0)

Caption: This photograph taken with a smartphone captures the ethereal beauty of the Northern Lights at Cassidy Point, Yellowknife, NT, Canada on 24 March 2023, at temperatures well below freezing (–29°C). The mesmerising dance of the Aurora Borealis (Australis), commonly known as the Northern (Southern) Lights, paints the night sky in striking hues. The aurora is a natural phenomenon caused by charged particles from the Sun interacting with Earth’s atmosphere, and being redirected by Earth’s magnetic field towards the north and south polar regions. The charged particles excite atoms and molecules in the atmosphere, resulting in a light display that varies in colour and form. The different colours of an aurora are determined by the gases (atoms and molecules) in Earth's atmosphere, the altitude of the aurora, the density of the atmosphere, and the energy of the charged particles. In general, green is attributed to oxygen molecules, red is associated with high-altitude oxygen molecules, purple and blue are associated with hydrogen and helium, and pink auroras are typically associated with nitrogen. On this particular night, the serene environment of Cassidy Point provided an unobstructed view of the lights. In the foreground, Aurora Village can be seen, a site renowned for organised tours to witness this spectacle.
Credit: Jason Johnson/IAU OAE (CC BY 4.0)

Caption: Second place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (still images) Aurorae often display waving curtain-like patterns where arcs or bands form moving curls, folds, or even spirals. These irregular shapes mirror the small-scale structure of Earth's magnetic field interacting with charged particle flows. Although the full Moon illuminates both the landscape and the night sky, the auroa is easily visible, which demonstrates that it can be a very bright and colourful phenomenon.
Credit: Rainer Sparenberg/IAU OAE

Caption: In the serene landscapes of Lofoten, Norway on 28 March 2023, the sky was set ablaze by the aurora. The Northern (Southern) Lights, also known as aurorae, are natural light displays resulting from interactions between solar winds and Earth’s magnetic fields, as charged particles are redirected towards the north and south pole regions. In Norse legends, they are often depicted as a heavenly fire. In this scene, the celestial show is beautifully complemented by the silhouette of a lighthouse, as if the lighthouse ignited the mesmerising display overhead. Caught off-guard by this dazzling spectacle, the photographer swiftly captured the moment with a smartphone. This is a testament to the breathtaking surprises nature offers and the impressive capabilities of modern devices.
Credit: Stephanie Ziyi Ye/IAU OAE (CC BY 4.0)

Caption: Second place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (time-lapses) This video shows how aurorae evolve slowly over timescales of a few minutes. Note the clouds being illuminated from behind in the last two shots. Aurorae are caused by interactions between the charged particles blown out in huge explosions from the Sun and the Earth's magnetic field. The changes over time are caused by huge waves of particles pushing the Earth's magnetic field into strange shapes before it snaps back into place.
Credit: Sergio Díaz Ruiz/IAU OAE

Caption: First place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (time-lapses). Aurorae are often called "Northern Lights" in Europe or North America but here we see that they also exist at the extreme south of our planet. Taken at Zhongshan Station, Antarctica, this time-lapse (speeded up) video shows how some bands of Aurora can remain stable over longer times while other features appear to "dance". See how many different patterns of swirls and waves you can spot in the video.
Credit: Hang Li/IAU OAE

Caption: Third place in the 2021 IAU OAE Astrophotography Contest, category Aurorae (time-lapses). This is a strange atmospheric phenomenon known as Steve. This is similar to an aurora as it is caused by charged particles interacting with the Earth's magnetic field. However unlike aurorae, the particles which cause Steve are generated high in the Earth's atmosphere rather than coming from the Sun. Note the banded "picket fence" appearance. This is caused by waves of these particles in the upper atmosphere. The name Steve was chosen by the first group to describe this phenomenon as a familiar name for something unknown. Sheila Wiwchar/IAU OAE
Credit: Wiwchar, Sheila; IAU OAE