Planetary alignment
See which planets are lined up right now on a live, top-down map of the Solar System. Turn on the alignments layer and run time to catch the next one.
What a planetary alignment really is
The planets orbit the Sun in nearly the same plane, the ecliptic, so from a top-down view they often seem to line up. A real alignment is when two or more planets share almost the same direction, either on the same side of the Sun or on opposite sides. Because each orbit is tilted by a few degrees, a perfectly straight line never forms; astronomers speak of planets being aligned when they fall within a few degrees of each other.
How to use the map
The "Alignments" layer is on by default: violet lines connect planets that are lined up at the shown date. Drag the day slider or press a speed button to run time and watch alignments form and break. Click any body to see its live distance, compare two of them, or use "Next event" to jump to the next close approach.
Do alignments mean anything?
They are a viewing opportunity, nothing more. The gravitational pull of the planets on Earth is vanishingly small next to the Moon and the Sun, so an alignment has no physical effect here. What it does offer is a chance to spot several planets in one night, which is genuinely beautiful.
See also: planets today, Astronomy.
Frequently asked questions
What is a planetary alignment?
It is when several planets gather in roughly the same region of the sky as seen from Earth, or line up along the same direction from the Sun. A perfect straight line never happens because each planet orbits in a slightly different plane, so "alignment" means they appear close together within a few degrees.
Are the planets aligned today?
Use the live map above: turn on the "Alignments" layer and run time with the slider or the speed buttons. The map marks every pair of planets that are currently lined up (same direction or opposite sides of the Sun).
How rare is a full planetary alignment?
Loose groupings of several bright planets happen every year or two. A tight gathering of all the naked-eye planets in a small patch of sky is rare, occurring only a few times per century. A literal straight line of all eight planets does not occur on human timescales.
Do planetary alignments affect Earth?
No. The combined gravity of the planets on Earth is negligible compared with the Moon and the Sun. Alignments are a beautiful sky sight, not a physical event with effects on our planet.