← Another date

Birthday · October 20, 2017

A Beautiful Trifid

October 20, 2017

The constellations may be old, but the person celebrating beneath them is gloriously new by cosmic standards.

A Beautiful Trifid

A little universe, just for you

Your date.
Ready to give.

Free PNG · 1080 × 1350 · No account needed

Image rights and credit requirements apply when sharing or reusing imagery.

Change the year

APOD published October 20, 2017. Credit: Chamaeleon Team. A publication-date match, not a photo taken on your date. Independent of NASA.

Behind the image

A Beautiful Trifid

Original APOD · October 20, 2017

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. But the red emission region roughly separated into three parts by obscuring dust lanes is what lends the Trifid its popular name. Pillars and jets sculpted by newborn stars, below and left of the emission nebula's center, appear in famous Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across. Just too faint to be seen by the unaided eye, it almost covers the area of the Moon in planet Earth's sky.

Image credit: Chamaeleon Team

Explore October 20 in other years