swap_horiz Planck Alternatives

1

Cassini-Huygens

The Cassini-Huygens mission, operated by NASA and ESA, was a space-based observatory dedicated to studying Saturn and it...

Decommissioned Nasa Planetary Space Based

9.8 Brilliant

2

Gaia

The Gaia observatory is a space-based mission operated by the European Space Agency. It meticulously surveys our galaxy,...

Survey Optical Space Based Astrometry

9.7 Brilliant

3

Kepler Space Telescope

The Kepler Space Telescope was a NASA observatory launched in 2009. It monitored over 150,000 stars for dips in brightne...

Decommissioned Optical Nasa Space Based

9.6 Brilliant

4

Hipparcos

Hipparcos was a European Space Agency observatory launched in 1989. It performed groundbreaking measurements of stellar...

Parallax Decommissioned Space Based Astrometry

9.4 Excellent

5

Galileo spacecraft

The Galileo spacecraft was a NASA observatory designed for planetary exploration of Jupiter and its moons. Launched in 1...

Decommissioned Nasa Planetary Jupiter

9.4 Excellent

6

SOHO

SOHO is a space-based observatory operated jointly by NASA and the European Space Agency. It monitors the Sun’s activity...

Solar Nasa Space Based Esa

9.3 Excellent

7

Spitzer Space Telescope

The Spitzer Space Telescope was a NASA space-based observatory operating from 2003 to 2020. It utilized infrared light t...

Survey Decommissioned Nasa Infrared

9.2 Excellent

8

Herschel Space Observatory

The Herschel Space Observatory is a decommissioned space-based observatory operated by the European Space Agency (ESA)....

Decommissioned Infrared Space Based Esa

9.1 Excellent

9

XMM-Newton

The XMM-Newton observatory, operated by ESA, observes the universe primarily in X-rays. Its large telescope allows for d...

High Energy Space Based X Ray Photometry

8.9 Great

10

Compton Gamma Ray Observatory

The Compton Gamma Ray Observatory was a NASA space-based observatory that operated from 1991 until its decommissioning i...

Decommissioned High Energy Nasa Space Based

8.9 Great

11

BeppoSAX

BeppoSAX was a European Space Agency observatory launched in 1996. This satellite primarily observed X-rays and gamma ra...

Historical Space Based X Ray Gamma Ray Bursts

8.9 Great

12

ROSAT

ROSAT was a German X-ray satellite launched in 1990 that produced the first all-sky survey of cosmic X-ray sources using...

Germany Decommissioned All Sky Space Based

8.6 Great

13

Hinode

Hinode, meaning sunrise, is a solar observation satellite launched by JAXA in 2006 to study the Sun's magnetic fields an...

Solar Space Based X Ray Esa

8.4 Great

14

RXTE

The Rossi X-ray Timing Explorer was a NASA satellite launched in 1995 to observe variability in X-ray emissions from bla...

Decommissioned Nasa Space Based Timing

8.4 Great

15

LISA Pathfinder

LISA Pathfinder was a European Space Agency spacecraft launched in 2015 to successfully test the technologies required f...

Decommissioned Space Based Gravitational Wave Esa

8.4 Great

16

IXPE

The Imaging X-ray Polarimetry Explorer is a NASA astrophysics satellite launched in 2021, notable for being the first de...

Nasa Space Based X Ray Esa

8.2 Great

17

Suzaku

Suzaku was a Japanese X-ray astronomy satellite launched in 2005, specifically designed to observe high-energy phenomena...

Decommissioned Space Based Spectroscopy X Ray

8.1 Great

18

INTEGRAL

INTEGRAL, launched by the European Space Agency in 2002, is a dedicated gamma-ray observatory designed to observe celest...

High Energy Space Based Gamma Ray X Ray

7.8 Good

19

EXOSAT

EXOSAT was a European Space Agency X-ray satellite launched in 1983 that operated for three years, studying galactic and...

Decommissioned Historical Space Based X Ray

7.6 Good

20

Astro-H / Hitomi

Hitomi was a Japanese X-ray astronomy satellite launched in 2016 by JAXA, though its mission ended prematurely due to an...

High Resolution Decommissioned Space Based X Ray

4.5 Poor