MTOF Proton Monitor

There is a problem with the motor controlling the High Gain Antenna on the SOHO spacecraft. Science data coverage may be less than complete for 1-2 weeks every 90 days (when the spacecraft gets 'flipped'). The next "keyhole" period can be found in this table.

Most Recent Shock Candidates:

Dates

24 Apr 2025

15 Apr 2025

21 Mar 2025

0609

1644

0139

day of year

114

105

080

F/R

fwd

Zone

Confidence Level

98%

99%

Current time in UTC

Two Day PM Plot — Data ending at 2315 GMT on April 24, 2025 (2 minute ascii data)

Two Week PM Plot — Data ending at 2353 GMT on April 23, 2025 (15 minute ascii data)

Where is SoHO?

The predicted position of the SOHO spacecraft in the GSE coordinate system (X,Y,Z) in Earth radii at 0610 GMT on Oct 15, 2020:

( 216, -103, 1 )

Daily Orbit Data:

Launch through 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 2023, 2024, 2025

What's being plotted?

What do the colors mean?

About the PM sensor

The SOHO mission

The Proton Monitor (PM) is one of the scientific sensors in the Charge, Element, and Isotope Analysis System (CELIAS) instrument package aboard the SOHO spacecraft.

LIVE from College Park...

the latest 48 hours of solar wind data

brought to you by the CELIAS/MTOF Proton Monitor on the SOHO Spacecraft

ISSI video: 25 Years of SOHO and First Glimpses of Parker Solar Probe and Solar Orbiter

Where is SoHO?