SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G
                                (RULE 13d - 102)

      INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO 13d-1(b),
            (c) AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO 13d

                                (Amendment No.)*
         Aether Systems, Inc.
-----------------------------
(Name of Issuer)

         Common Stock
-----------------------------
(Title of Class of Securities)

         00808V105
-----------------------------
(CUSIP Number)

         September 24, 2004
-----------------------------
(Date of Event which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

[ ]      Rule 13d-1(b)
[x]      Rule 13d-1(c)
[ ]      Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).







1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth LLC

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Cayman Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  2,697,476

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  2,697,476

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%

12.      TYPE OF REPORTING PERSON*

                  CO
                      *SEE INSTRUCTIONS BEFORE FILLING OUT!


1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Amaranth Advisors L.L.C.

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  2,697,476

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  2,697,476

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%

12.      TYPE OF REPORTING PERSON*

                  IA

                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


1.       NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                  Nicholas M. Maounis

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

         (a)      [ ]
         (b)      [x]

3.       SEC USE ONLY

4.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.       SOLE VOTING POWER

                  0

6.       SHARED VOTING POWER

                  2,697,476

7.       SOLE DISPOSITIVE POWER

                  0

8.       SHARED DISPOSITIVE POWER

                  2,697,476

9.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  See 6 and 8 above.

10.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9)
         EXCLUDES CERTAIN SHARES*   [ ]

11.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

                  6.2%

12.      TYPE OF REPORTING PERSON*

                  IN, HC

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!


ITEM 1(a).        Name of Issuer:

         Aether Systems, Inc.

Item 1(b).        Address of Issuer's Principal Executive Offices:

11500 Cronridge Drive
Suite 110
Owings Mills, MD 21117


Item 2(a).        Name of Persons Filing:
Item 2(b).        Address of Principal Business Office or, if None, Residence:
Item 2(c).        Citizenship:

         Amaranth LLC
         c/o Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         Cayman Islands company

         Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         Delaware limited liability company

         Nicholas M. Maounis
         c/o Amaranth Advisors L.L.C.
         One American Lane
         Greenwich, Connecticut 06831
         U.S. Citizen

Amaranth  Advisors L.L.C.  is the trading advisor for Amaranth LLC  ("Amaranth")
and has been granted investment discretion over portfolio investments, including
the Common Stock (as defined below),  held by it. Maounis is the managing member
of  Amaranth  Advisors  L.L.C.  and may,  by virtue of his  position as managing
member, be deemed to have power to direct the vote and disposition of the Common
Stock held for Amaranth.


Item 2(d).        Title of Class of Securities

         Common Stock, $.01 Par Value ("Common Stock")

Item 2(e).        CUSIP Number:     00808V105




Item 3. If This  Statement is Filed  Pursuant to Rule  13d-1(b),  or 13d-2(b) or
        (c), Check Whether the Person Filing is a:

          (a)     [ ]   Broker or dealer registered under Section 15 of the
                        Exchange Act.

          (b)     [ ]   Bank as defined in Section 3(a)(6) of the Exchange Act.

          (c)     [ ]   Insurance company defined in Section 3(a)(19) of the
                        Exchange Act.

          (d)     [ ]   Investment company registered under Section 8 of the
                        Investment Company Act.

          (e)     [ ]   An investment adviser in accordance with
                        Rule 13d-1(b)(1)(ii)(E).

          (f)     [ ]   An employee benefit plan or endowment fund in
                        accordance with Rule 13d-1(b)(1)(ii)(F).

          (g)     [ ]   A parent holding company or control person in
                        accordance with Rule 13d-1(b)(1)(ii)(G).

          (h)     [ ]   A savings association as defined in Section 3(b) of
                        the Federal Deposit Insurance Act.

          (i)     [ ]   A church plan that is excluded from the  definition
                        of an investment  company under Section 3(c)(14) of
                        the Investment Company Act;

          (j)     [ ]   Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If this statement is filed pursuant to Rule 13d-1(c), check this box [x]

Item 4.   Ownership.

          Provide  the  following  information  regarding  the  aggregate
          number  and  percentage  of the class of securities of the issuer
          identified in Item 1.

(a)       Amount beneficially owned:

                  2,697,476


(b)       Percent of class:

                  6.2%

(c)       Number of shares as to which such person has:

                   (i)  Sole power to vote or direct the vote

                           0




                  (ii)  Shared power to vote or to direct the vote

                           See Item 4(a).

                  (iii)  Sole power to dispose or to direct the disposition of

                           0

                  (iv)  Shared power to dispose or to direct the disposition of

                           See Item 4(a).


Item 5.   Ownership of Five Percent or Less of a Class.

If this  statement  is being filed to report the fact that as of the date hereof
the Reporting  Persons have ceased to be the beneficial  owner of more than five
percent of the class of securities, check the following [ ]. Not applicable.

Item 6.   Ownership of More than Five Percent on Behalf of Another Person.

Shareholders  of Amaranth  indirectly  participate  in the receipt of  dividends
from,  and  proceeds  from the sale of, the Common Stock held for the account of
Amaranth.

Item 7.   Identification  and Classification of the Subsidiary Which Acquired
          the Security Being Reported on by the Parent Holding Company.

          Not applicable.

Item 8.   Identification and Classification of Members of the Group.

          See Item 2 in lieu of an Exhibit.

Item 9.   Notice of Dissolution of Group.

          Not applicable.


Item 10.  Certification.

By signing below the  undersigned  certifies  that, to the best of its knowledge
and belief, the securities  referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing  the control of
the  issuer  of the  securities  and  were  not  acquired  and are  not  held in
connection  with or as a participant in any  transaction  having that purpose or
effect.



                                   SIGNATURES

          After reasonable  inquiry and to the best of its knowledge and belief,
     each of the undersigned  certifies that the information  with respect to it
     set forth in this statement is true, complete, and correct.


Dated:    October 4, 2004

          AMARANTH  LLC,
                   by Amaranth Advisors L.L.C., as Trading Advisor

                   By:  /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis,
                        Managing Member


          AMARANTH ADVISORS L.L.C.

                   By:  /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis,
                        Managing Member




          /s/ Nicholas M. Maounis
          -----------------------
              Nicholas M. Maounis




                                    EXHIBIT A
                             JOINT FILING AGREEMENT

     The  undersigned  hereby agree that the statement on Schedule 13G signed by
     each  of  the  undersigned  shall  be,  filed  on  behalf  of  each  of the
     undersigned  pursuant  to and in  accordance  with the  provisions  of Rule
     13d-1(k) under the Securities Exchange Act of 1934, as amended.

Dated:    October 4, 2004

          AMARANTH LLC
                   by Amaranth Advisors L.L.C., as Trading Advisor

                   By:  /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis,
                        Managing Member


          AMARANTH ADVISORS L.L.C.

                   By:  /s/ Nicholas M. Maounis
                        -----------------------
                        Nicholas M. Maounis,
                        Managing Member





          /s/ Nicholas M. Maounis
          -----------------------
              Nicholas M. Maounis