Join Donate

Emily LakdawallaDecember 14, 2011

Video: Comet Lovejoy entered SOHO's LASCO C3 field of view this morning!

Jason Davis has been following the sunward dive of comet Lovejoy, and this morning he put together a spiffy animation of the comet entering the field of view of one of SOHO's Sun-monitoring cameras. SOHO has three coronagraphs, cameras built with an opaque disk that blocks light coming directly from the Sun. These allow SOHO to image the Sun's corona and coronal mass ejections, and also permit the cameras to see stars, planets, and comets near the Sun's position in SOHO's sky. SOHO's coronagraphs are called LASCO (Large Aperture Solar Coronagraph) C1, C2, and C3. C3 has the widest field of view, 32 solar radii; C2, a medium 6 solar radii; and C1 a narrow 3 solar radii. It's in C2 and C3 that we can see comets, and Lovejoy has, as of this morning, entered the C3 field of view.

Here's a still from that animation. This will be a fascinating event to watch as 2011 draws to a close! The comet is supposed to reach perihelion tomorrow.

Sungrazing Comet Lovejoy seen in SOHO LASCO C3


Sungrazing Comet Lovejoy seen in SOHO LASCO C3

Jason was able to make that animation because SOHO is one of the missions that puts all its data online in near-real-time. With these data, armchair astronomers can discover new comets in the SOHO data. Visit the Sungrazing Comets website to learn more about how you can participate in that.

Now, here's a public service announcement. The Sun is getting pretty active. It spits out coronal mass ejections a lot. There is a distinct chance that as Lovejoy approaches the Sun, there will be a coronal mass ejection. Our brains are wired to see causation when two strange (to us) events happen at nearly the same time. But a teeny tiny comet can't cause a coronal mass ejection. The comet is like a seagull, and the Sun an ocean. When a seagull flies over the shore and a wave washes in, did the seagull cause the wave? Nope. Waves happen all the time, and seagulls are too tiny to have any effect on the ocean. This is the same.

Read more: comets, the Sun, solar observing spacecraft

You are here:
Emily Lakdawalla 2017 headshot square serene
Emily Lakdawalla

Solar System Specialist for The Planetary Society
Read more articles by Emily Lakdawalla

Comments & Sharing
Bill Nye and people
Let's Change the World

Become a member of The Planetary Society and together we will create the future of space exploration.

Join Today

The Planetary Fund

Help advance robotic and human space exploration, defend our planet, and search for life.


"We're changing the world. Are you in?"
- CEO Bill Nye

Sign Up for Email Updates