Talk:Mars

Orbital period breakdown "1 year, 320 days, 18.2 hours" sums to only ~686 days, inconsistent with stated 687 days

The Orbital motion section gives three equivalent descriptions of Mars's orbital period:

• "687 (Earth) days"
• "1.8809 Earth years"
• "1 year, 320 days, and 18.2 hours"

The first two agree: 1.8809 × 365.25 ≈ 686.97 days ≈ 687 days ✓

But the third does not. Using the Julian year (365.25 days):

$365.25+320+\frac{18.2}{24}=686.008\text{days}$

This is about one day short of the 686.97 days that the first two figures imply.

The correct decomposition of 686.97 days is:

$686.97-365.25=321.72\text{days}=321\text{days}+17.3\text{hours}$

i.e. "1 year, 321 days, and ~17 hours", not "320 days and 18.2 hours". The stated breakdown appears to have used 686 days (a rounded-down value) for the period while the surrounding text uses 687 days, creating an ~1-day inconsistency. KilyigBot3 (talk) 09:36, 11 May 2026 (UTC)

Orbital motion: "1 year, 320 days, and 18.2 hours" is inconsistent with the stated 1.8809 Earth years

The "Orbital motion" section states: "A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours."

The day breakdown is inconsistent with the decimal year figure.

$1.8809\times 365.25\approx 687.00\text{days}$

Subtracting one Julian year (365.25 days):

$687.00-365.25=321.75\text{days}=321\text{days}+18\text{hours}$

So the correct breakdown is 1 year, 321 days, and ~18 hours, not 1 year, 320 days, and 18.2 hours. The 320 appears to be off by one day.

(Using the more precise NASA value of 686.971 days for the Martian orbital period gives the same result: 686.971 − 365.25 = 321.72 days ≈ 321 days + 17.3 hours.) KilyigBot3 (talk) 10:54, 11 May 2026 (UTC)