in the Making?
hypothesis for the origin of our Solar System has been bolstered by a
variety of recent observations that look very much like star and planetary
systems in various stages of formation.
New Solar Systems
Telescope observations shed considerable light on the
birth of stars and associated planetary systems. The
following image shows regions in the
Orion Nebula where solar systems may be forming.
Regions in the Orion Nebula where solar systems appear to be forming
The Orion Nebula is approximately 1500 light years from Earth. It is
visible to the naked eye as the
middle "star" in the sword of the
These images were taken with the
Wide Field Planetary Camera 2 of
the Hubble Space
Telescope (C.R. O'Dell,
Details of the
images show several protoplanetary disks (
including a single
dark disk surrounding a central
(Ref). The lower left inset figure shows a drawing giving the approximate
scale of our Solar System relative to the proplyd.
Here is a
movie illustrating these protoplanetary disks in the Orion Nebula
of these planetary systems now forming in Orion.
More Star-Forming Regions
Many other star-forming
regions are known. In addition to the Eagle Nebula discussed below, here are
images and discussion of
In each of these examples there is strong evidence that stars are being born in
the region shown in the image; presumably, at least in some of the cases,
attendant solar systems are being formed also.
Star Formation in the Eagle Nebula
The following images show examples in the Eagle Nebula of regions where stars
(and possibly solar systems) appear to be forming.
Star-Birth Clouds in M16 (Eagle Nebula). J. Hester and P. Scowon (Arizona St.
Univ.), November 2, 1995. Taken with NASA Hubble Space Telescope, WFPC2
The scale of the image on the left is about 1 light year. The blowup on the
right shows finger-like structures that are thought to be regions in which new
stars are being formed. The tips of these finger-like objects are about the
size of our Solar System! Here is a movie of these
star-forming regions in the Eagle Nebula made with the Hubble Space Telescope
This movie is about as close as you are ever going to get to the bridge of the
Planets Around other Stars
In recent years rather conclusive evidence has accumulated for planets orbiting
other stars. This evidence comes from the gravitational perturbations exerted
on the star by the unseen companion planet
that can be exposed by very accurate
measurement of the radial velocity of the star
(see the related discussion of detecting unseen companions in
binary star systems). These measurements require
that variations in the radial velocity of order 10 meters per second be detected
relative to a total radial velocity typically of order 10-100
kilometers per second. Here is
about some of the first discovered planets, and here is an online
Extrasolar Planets Encyclopedia
with some catalogs.
There are currently (2004) 120 confirmed extra-solar planets
in 105 extra-solar planetary systems.